Array.Sort Array.Sort Array.Sort Array.Sort Method

Definition

Sorts the elements in a one-dimensional array.

Overloads

Sort(Array, Int32, Int32, IComparer) Sort(Array, Int32, Int32, IComparer) Sort(Array, Int32, Int32, IComparer)

Sorts the elements in a range of elements in a one-dimensional Array using the specified IComparer.

Sort(Array, Array, Int32, Int32, IComparer) Sort(Array, Array, Int32, Int32, IComparer) Sort(Array, Array, Int32, Int32, IComparer) Sort(Array, Array, Int32, Int32, IComparer)

Sorts a range of elements in a pair of one-dimensional Array objects (one contains the keys and the other contains the corresponding items) based on the keys in the first Array using the specified IComparer.

Sort(Array, Int32, Int32) Sort(Array, Int32, Int32) Sort(Array, Int32, Int32)

Sorts the elements in a range of elements in a one-dimensional Array using the IComparable implementation of each element of the Array.

Sort(Array, Array, Int32, Int32) Sort(Array, Array, Int32, Int32) Sort(Array, Array, Int32, Int32) Sort(Array, Array, Int32, Int32)

Sorts a range of elements in a pair of one-dimensional Array objects (one contains the keys and the other contains the corresponding items) based on the keys in the first Array using the IComparable implementation of each key.

Sort(Array, IComparer) Sort(Array, IComparer) Sort(Array, IComparer)

Sorts the elements in a one-dimensional Array using the specified IComparer.

Sort(Array, Array, IComparer) Sort(Array, Array, IComparer) Sort(Array, Array, IComparer) Sort(Array, Array, IComparer)

Sorts a pair of one-dimensional Array objects (one contains the keys and the other contains the corresponding items) based on the keys in the first Array using the specified IComparer.

Sort(Array, Array) Sort(Array, Array) Sort(Array, Array) Sort(Array, Array)

Sorts a pair of one-dimensional Array objects (one contains the keys and the other contains the corresponding items) based on the keys in the first Array using the IComparable implementation of each key.

Sort(Array) Sort(Array) Sort(Array)

Sorts the elements in an entire one-dimensional Array using the IComparable implementation of each element of the Array.

Sort<T>(T[]) Sort<T>(T[]) Sort<T>(T[]) Sort<T>(T[])

Sorts the elements in an entire Array using the IComparable<T> generic interface implementation of each element of the Array.

Sort<T>(T[], IComparer<T>) Sort<T>(T[], IComparer<T>) Sort<T>(T[], IComparer<T>) Sort<T>(T[], IComparer<T>)

Sorts the elements in an Array using the specified IComparer<T> generic interface.

Sort<T>(T[], Comparison<T>) Sort<T>(T[], Comparison<T>) Sort<T>(T[], Comparison<T>) Sort<T>(T[], Comparison<T>)

Sorts the elements in an Array using the specified Comparison<T>.

Sort<T>(T[], Int32, Int32) Sort<T>(T[], Int32, Int32) Sort<T>(T[], Int32, Int32) Sort<T>(T[], Int32, Int32)

Sorts the elements in a range of elements in an Array using the IComparable<T> generic interface implementation of each element of the Array.

Sort<T>(T[], Int32, Int32, IComparer<T>) Sort<T>(T[], Int32, Int32, IComparer<T>) Sort<T>(T[], Int32, Int32, IComparer<T>) Sort<T>(T[], Int32, Int32, IComparer<T>)

Sorts the elements in a range of elements in an Array using the specified IComparer<T> generic interface.

Sort<TKey,TValue>(TKey[], TValue[]) Sort<TKey,TValue>(TKey[], TValue[]) Sort<TKey,TValue>(TKey[], TValue[]) Sort<TKey,TValue>(TKey[], TValue[])

Sorts a pair of Array objects (one contains the keys and the other contains the corresponding items) based on the keys in the first Array using the IComparable<T> generic interface implementation of each key.

Sort<TKey,TValue>(TKey[], TValue[], IComparer<TKey>) Sort<TKey,TValue>(TKey[], TValue[], IComparer<TKey>) Sort<TKey,TValue>(TKey[], TValue[], IComparer<TKey>) Sort<TKey,TValue>(TKey[], TValue[], IComparer<TKey>)

Sorts a pair of Array objects (one contains the keys and the other contains the corresponding items) based on the keys in the first Array using the specified IComparer<T> generic interface.

Sort<TKey,TValue>(TKey[], TValue[], Int32, Int32) Sort<TKey,TValue>(TKey[], TValue[], Int32, Int32) Sort<TKey,TValue>(TKey[], TValue[], Int32, Int32) Sort<TKey,TValue>(TKey[], TValue[], Int32, Int32)

Sorts a range of elements in a pair of Array objects (one contains the keys and the other contains the corresponding items) based on the keys in the first Array using the IComparable<T> generic interface implementation of each key.

Sort<TKey,TValue>(TKey[], TValue[], Int32, Int32, IComparer<TKey>) Sort<TKey,TValue>(TKey[], TValue[], Int32, Int32, IComparer<TKey>) Sort<TKey,TValue>(TKey[], TValue[], Int32, Int32, IComparer<TKey>) Sort<TKey,TValue>(TKey[], TValue[], Int32, Int32, IComparer<TKey>)

Sorts a range of elements in a pair of Array objects (one contains the keys and the other contains the corresponding items) based on the keys in the first Array using the specified IComparer<T> generic interface.

Sort(Array, Int32, Int32, IComparer) Sort(Array, Int32, Int32, IComparer) Sort(Array, Int32, Int32, IComparer)

Sorts the elements in a range of elements in a one-dimensional Array using the specified IComparer.

public:
 static void Sort(Array ^ array, int index, int length, System::Collections::IComparer ^ comparer);
public static void Sort (Array array, int index, int length, System.Collections.IComparer comparer);
static member Sort : Array * int * int * System.Collections.IComparer -> unit

Parameters

array
Array Array Array Array

The one-dimensional Array to sort.

index
Int32 Int32 Int32 Int32

The starting index of the range to sort.

length
Int32 Int32 Int32 Int32

The number of elements in the range to sort.

comparer
IComparer IComparer IComparer IComparer

The IComparer implementation to use when comparing elements.

-or-

null to use the IComparable implementation of each element.

Exceptions

index is less than the lower bound of array.

-or-

length is less than zero.

index and length do not specify a valid range in array.

-or-

The implementation of comparer caused an error during the sort. For example, comparer might not return 0 when comparing an item with itself.

comparer is null, and one or more elements in array do not implement the IComparable interface.

Examples

The following code example shows how to sort the values in an Array using the default comparer and a custom comparer that reverses the sort order. Note that the result might vary depending on the current CultureInfo.

using namespace System;
using namespace System::Collections;

public ref class ReverseComparer : IComparer
{
public:
   // Call CaseInsensitiveComparer::Compare with the parameters reversed.
   virtual int Compare(Object^ x, Object^ y) = IComparer::Compare
   {
      return ((gcnew CaseInsensitiveComparer)->Compare(y, x));
   }
};

void DisplayValues(array<String^>^ arr)
{
   for (int i = arr->GetLowerBound(0); i <= arr->GetUpperBound(0); i++)
      Console::WriteLine( "   [{0}] : {1}", i, arr[ i ] );

   Console::WriteLine();
}

int main()
{
   // Create and initialize a new array. and a new custom comparer.
   array<String^>^ words = { "The","QUICK","BROWN","FOX","jumps",
                             "over","the","lazy","dog" };
   // Instantiate the reverse comparer.
   IComparer^ revComparer = gcnew ReverseComparer();
   
   // Display the values of the Array.
   Console::WriteLine( "The original order of elements in the array:" );
   DisplayValues(words);

   // Sort a section of the array using the default comparer.
   Array::Sort(words, 1, 3);
   Console::WriteLine( "After sorting elements 1-3 by using the default comparer:");
   DisplayValues(words);

   // Sort a section of the array using the reverse case-insensitive comparer.
   Array::Sort(words, 1, 3, revComparer);
   Console::WriteLine( "After sorting elements 1-3 by using the reverse case-insensitive comparer:");
   DisplayValues(words);

   // Sort the entire array using the default comparer.
   Array::Sort(words);
   Console::WriteLine( "After sorting the entire array by using the default comparer:");
   DisplayValues(words);

   // Sort the entire array by using the reverse case-insensitive comparer.
   Array::Sort(words, revComparer);
   Console::WriteLine( "After sorting the entire array using the reverse case-insensitive comparer:");
   DisplayValues(words);
}

/* 
This code produces the following output.

The Array initially contains the following values:
   [0] : The
   [1] : QUICK
   [2] : BROWN
   [3] : FOX
   [4] : jumps
   [5] : over
   [6] : the
   [7] : lazy
   [8] : dog

After sorting a section of the Array using the default comparer:
   [0] : The
   [1] : BROWN
   [2] : FOX
   [3] : QUICK
   [4] : jumps
   [5] : over
   [6] : the
   [7] : lazy
   [8] : dog

After sorting a section of the Array using the reverse case-insensitive comparer:
   [0] : The
   [1] : QUICK
   [2] : FOX
   [3] : BROWN
   [4] : jumps
   [5] : over
   [6] : the
   [7] : lazy
   [8] : dog

After sorting the entire Array using the default comparer:
   [0] : BROWN
   [1] : dog
   [2] : FOX
   [3] : jumps
   [4] : lazy
   [5] : over
   [6] : QUICK
   [7] : the
   [8] : The

After sorting the entire Array using the reverse case-insensitive comparer:
   [0] : the
   [1] : The
   [2] : QUICK
   [3] : over
   [4] : lazy
   [5] : jumps
   [6] : FOX
   [7] : dog
   [8] : BROWN

*/
using System;
using System.Collections;

public class ReverseComparer : IComparer  
{
   // Call CaseInsensitiveComparer.Compare with the parameters reversed.
   public int Compare(Object x, Object y)  
   {
       return (new CaseInsensitiveComparer()).Compare(y, x );
   }
}

public class Example 
{
   public static void Main()  
   {
      // Create and initialize a new array. 
      String[] words = { "The", "QUICK", "BROWN", "FOX", "jumps", 
                         "over", "the", "lazy", "dog" };
      // Instantiate the reverse comparer.
      IComparer revComparer = new ReverseComparer();
 
      // Display the values of the array.
      Console.WriteLine( "The original order of elements in the array:" );
      DisplayValues(words);
 
      // Sort a section of the array using the default comparer.
      Array.Sort(words, 1, 3);
      Console.WriteLine( "After sorting elements 1-3 by using the default comparer:");
      DisplayValues(words);

      // Sort a section of the array using the reverse case-insensitive comparer.
      Array.Sort(words, 1, 3, revComparer);
      Console.WriteLine( "After sorting elements 1-3 by using the reverse case-insensitive comparer:");
      DisplayValues(words);

      // Sort the entire array using the default comparer.
      Array.Sort(words);
      Console.WriteLine( "After sorting the entire array by using the default comparer:");
      DisplayValues(words);

      // Sort the entire array by using the reverse case-insensitive comparer.
      Array.Sort(words, revComparer);
      Console.WriteLine( "After sorting the entire array using the reverse case-insensitive comparer:");
      DisplayValues(words);
   }
 
   public static void DisplayValues(String[] arr)  
   {
      for ( int i = arr.GetLowerBound(0); i <= arr.GetUpperBound(0);
            i++ )  {
         Console.WriteLine( "   [{0}] : {1}", i, arr[i] );
      }
      Console.WriteLine();
   }
}
// The example displays the following output:
//    The original order of elements in the array:
//       [0] : The
//       [1] : QUICK
//       [2] : BROWN
//       [3] : FOX
//       [4] : jumps
//       [5] : over
//       [6] : the
//       [7] : lazy
//       [8] : dog
//    
//    After sorting elements 1-3 by using the default comparer:
//       [0] : The
//       [1] : BROWN
//       [2] : FOX
//       [3] : QUICK
//       [4] : jumps
//       [5] : over
//       [6] : the
//       [7] : lazy
//       [8] : dog
//    
//    After sorting elements 1-3 by using the reverse case-insensitive comparer:
//       [0] : The
//       [1] : QUICK
//       [2] : FOX
//       [3] : BROWN
//       [4] : jumps
//       [5] : over
//       [6] : the
//       [7] : lazy
//       [8] : dog
//    
//    After sorting the entire array by using the default comparer:
//       [0] : BROWN
//       [1] : dog
//       [2] : FOX
//       [3] : jumps
//       [4] : lazy
//       [5] : over
//       [6] : QUICK
//       [7] : the
//       [8] : The
//    
//    After sorting the entire array using the reverse case-insensitive comparer:
//       [0] : the
//       [1] : The
//       [2] : QUICK
//       [3] : over
//       [4] : lazy
//       [5] : jumps
//       [6] : FOX
//       [7] : dog
//       [8] : BROWN    
Imports System.Collections

Public Class ReverseComparer : Implements IComparer
   ' Call CaseInsensitiveComparer.Compare with the parameters reversed.
   Function Compare(x As Object, y As Object) As Integer _
            Implements IComparer.Compare
      Return New CaseInsensitiveComparer().Compare(y, x)
   End Function 
End Class

Public Module Example
   Public Sub Main()
      ' Create and initialize a new array.
      Dim words() As String =  { "The", "QUICK", "BROWN", "FOX", "jumps", 
                                 "over", "the", "lazy", "dog" }
      ' Instantiate a new custom comparer.
      Dim revComparer As New ReverseComparer()

      ' Display the values of the array.
      Console.WriteLine( "The original order of elements in the array:" )
      DisplayValues(words)

      ' Sort a section of the array using the default comparer.
      Array.Sort(words, 1, 3)
      Console.WriteLine( "After sorting elements 1-3 by using the default comparer:")
      DisplayValues(words)

      ' Sort a section of the array using the reverse case-insensitive comparer.
      Array.Sort(words, 1, 3, revComparer)
      Console.WriteLine( "After sorting elements 1-3 by using the reverse case-insensitive comparer:")
      DisplayValues(words)

      ' Sort the entire array using the default comparer.
      Array.Sort(words)
      Console.WriteLine( "After sorting the entire array by using the default comparer:")
      DisplayValues(words)

      ' Sort the entire array by using the reverse case-insensitive comparer.
      Array.Sort(words, revComparer)
      Console.WriteLine( "After sorting the entire array using the reverse case-insensitive comparer:")
      DisplayValues(words)
   End Sub 

   Public Sub DisplayValues(arr() As String)
      For i As Integer = arr.GetLowerBound(0) To arr.GetUpperBound(0)
         Console.WriteLine("   [{0}] : {1}", i, arr(i))
      Next 
      Console.WriteLine()
   End Sub 
End Module 
' The example displays the following output:
'    The original order of elements in the array:
'       [0] : The
'       [1] : QUICK
'       [2] : BROWN
'       [3] : FOX
'       [4] : jumps
'       [5] : over
'       [6] : the
'       [7] : lazy
'       [8] : dog
'    
'    After sorting elements 1-3 by using the default comparer:
'       [0] : The
'       [1] : BROWN
'       [2] : FOX
'       [3] : QUICK
'       [4] : jumps
'       [5] : over
'       [6] : the
'       [7] : lazy
'       [8] : dog
'    
'    After sorting elements 1-3 by using the reverse case-insensitive comparer:
'       [0] : The
'       [1] : QUICK
'       [2] : FOX
'       [3] : BROWN
'       [4] : jumps
'       [5] : over
'       [6] : the
'       [7] : lazy
'       [8] : dog
'    
'    After sorting the entire array by using the default comparer:
'       [0] : BROWN
'       [1] : dog
'       [2] : FOX
'       [3] : jumps
'       [4] : lazy
'       [5] : over
'       [6] : QUICK
'       [7] : the
'       [8] : The
'    
'    After sorting the entire array using the reverse case-insensitive comparer:
'       [0] : the
'       [1] : The
'       [2] : QUICK
'       [3] : over
'       [4] : lazy
'       [5] : jumps
'       [6] : FOX
'       [7] : dog
'       [8] : BROWN

Remarks

If comparer is null, each element within the specified range of elements in array must implement the IComparable interface to be capable of comparisons with every other element in array.

If the sort is not successfully completed, the results are undefined.

The .NET Framework includes predefined IComparer implementations listed in the following table.

Implementation Description
System.Collections.CaseInsensitiveComparer Compares any two objects, but performs a case-insensitive comparison of strings.
Comparer.Default Compares any two objects by using the sorting conventions of the current culture.
Comparer.DefaultInvariant Compares any two objects by using the sorting conventions of the invariant culture.
Comparer<T>.Default Compares two objects of type T by using the type's default sort order.

You can also support custom comparisons by providing an instance of your own IComparer implementation to the comparer parameter. The example does this by defining a ReverseComparer class that reverses the default sort order for instances of a type and performs case-insensitive string comparison.

This method uses the introspective sort (introsort) algorithm as follows:

  • If the partition size is fewer than 16 elements, it uses an insertion sort algorithm.

  • If the number of partitions exceeds 2 * LogN, where N is the range of the input array, it uses a Heapsort algorithm.

  • Otherwise, it uses a Quicksort algorithm.

This implementation performs an unstable sort; that is, if two elements are equal, their order might not be preserved. In contrast, a stable sort preserves the order of elements that are equal.

For arrays that are sorted by using the Heapsort and Quicksort algorithms, in the worst case, this method is an O(n log n) operation, where n is length.

Notes to Callers

The .NET Framework 4 and earlier versions used only the Quicksort algorithm. Quicksort identifies invalid comparers in some situations in which the sorting operation throws an IndexOutOfRangeException exception, and throws an ArgumentException exception to the caller. Starting with the .NET Framework 4.5, it is possible that sorting operations that previously threw ArgumentException will not throw an exception, because the insertion sort and heapsort algorithms do not detect an invalid comparer. For the most part, this applies to arrays with fewer than 16 elements.

See also

Sort(Array, Array, Int32, Int32, IComparer) Sort(Array, Array, Int32, Int32, IComparer) Sort(Array, Array, Int32, Int32, IComparer) Sort(Array, Array, Int32, Int32, IComparer)

Sorts a range of elements in a pair of one-dimensional Array objects (one contains the keys and the other contains the corresponding items) based on the keys in the first Array using the specified IComparer.

public:
 static void Sort(Array ^ keys, Array ^ items, int index, int length, System::Collections::IComparer ^ comparer);
public static void Sort (Array keys, Array items, int index, int length, System.Collections.IComparer comparer);
static member Sort : Array * Array * int * int * System.Collections.IComparer -> unit
Public Shared Sub Sort (keys As Array, items As Array, index As Integer, length As Integer, comparer As IComparer)

Parameters

keys
Array Array Array Array

The one-dimensional Array that contains the keys to sort.

items
Array Array Array Array

The one-dimensional Array that contains the items that correspond to each of the keys in the keysArray.

-or-

null to sort only the keysArray.

index
Int32 Int32 Int32 Int32

The starting index of the range to sort.

length
Int32 Int32 Int32 Int32

The number of elements in the range to sort.

comparer
IComparer IComparer IComparer IComparer

The IComparer implementation to use when comparing elements.

-or-

null to use the IComparable implementation of each element.

Exceptions

The keysArray is multidimensional.

-or-

The itemsArray is multidimensional.

index is less than the lower bound of keys.

-or-

length is less than zero.

items is not null, and the lower bound of keys does not match the lower bound of items.

-or-

items is not null, and the length of keys is greater than the length of items.

-or-

index and length do not specify a valid range in the keysArray.

-or-

items is not null, and index and length do not specify a valid range in the itemsArray.

-or-

The implementation of comparer caused an error during the sort. For example, comparer might not return 0 when comparing an item with itself.

comparer is null, and one or more elements in the keysArray do not implement the IComparable interface.

Examples

The following code example shows how to sort two associated arrays where the first array contains the keys and the second array contains the values. Sorts are done using the default comparer and a custom comparer that reverses the sort order. Note that the result might vary depending on the current CultureInfo.

using namespace System;
using namespace System::Collections;

public ref class myReverserClass: public IComparer
{
private:

   // Calls CaseInsensitiveComparer::Compare with the parameters reversed.
   virtual int Compare( Object^ x, Object^ y ) = IComparer::Compare
   {
      return ((gcnew CaseInsensitiveComparer)->Compare( y, x ));
   }
};

void PrintKeysAndValues( array<String^>^myKeys, array<String^>^myValues )
{
   for ( int i = 0; i < myKeys->Length; i++ )
   {
      Console::WriteLine( " {0, -10}: {1}", myKeys[ i ], myValues[ i ] );
   }
   Console::WriteLine();
}

int main()
{
   // Creates and initializes a new Array and a new custom comparer.
   array<String^>^myKeys = {"red","GREEN","YELLOW","BLUE","purple","black","orange"};
   array<String^>^myValues = {"strawberries","PEARS","LIMES","BERRIES","grapes","olives","cantaloupe"};
   IComparer^ myComparer = gcnew myReverserClass;

   // Displays the values of the Array.
   Console::WriteLine( "The Array initially contains the following values:" );
   PrintKeysAndValues( myKeys, myValues );

   // Sorts a section of the Array using the default comparer.
   Array::Sort( myKeys, myValues, 1, 3 );
   Console::WriteLine( "After sorting a section of the Array using the default comparer:" );

   // Sorts a section of the Array using the reverse case-insensitive comparer.
   Array::Sort( myKeys, myValues, 1, 3, myComparer );
   Console::WriteLine( "After sorting a section of the Array using the reverse case-insensitive comparer:" );
   PrintKeysAndValues( myKeys, myValues );

   // Sorts the entire Array using the default comparer.
   Array::Sort( myKeys, myValues );
   Console::WriteLine( "After sorting the entire Array using the default comparer:" );
   PrintKeysAndValues( myKeys, myValues );

   // Sorts the entire Array using the reverse case-insensitive comparer.
   Array::Sort( myKeys, myValues, myComparer );
   Console::WriteLine( "After sorting the entire Array using the reverse case-insensitive comparer:" );
   PrintKeysAndValues( myKeys, myValues );
}

/* 
This code produces the following output.

The Array initially contains the following values:
   red       : strawberries
   GREEN     : PEARS
   YELLOW    : LIMES
   BLUE      : BERRIES
   purple    : grapes
   black     : olives
   orange    : cantaloupe

After sorting a section of the Array using the default comparer:
   red       : strawberries
   BLUE      : BERRIES
   GREEN     : PEARS
   YELLOW    : LIMES
   purple    : grapes
   black     : olives
   orange    : cantaloupe

After sorting a section of the Array using the reverse case-insensitive comparer:
   red       : strawberries
   YELLOW    : LIMES
   GREEN     : PEARS
   BLUE      : BERRIES
   purple    : grapes
   black     : olives
   orange    : cantaloupe

After sorting the entire Array using the default comparer:
   black     : olives
   BLUE      : BERRIES
   GREEN     : PEARS
   orange    : cantaloupe
   purple    : grapes
   red       : strawberries
   YELLOW    : LIMES

After sorting the entire Array using the reverse case-insensitive comparer:
   YELLOW    : LIMES
   red       : strawberries
   purple    : grapes
   orange    : cantaloupe
   GREEN     : PEARS
   BLUE      : BERRIES
   black     : olives

*/
using System;
using System.Collections;

public class SamplesArray  {
 
   public class myReverserClass : IComparer  {

      // Calls CaseInsensitiveComparer.Compare with the parameters reversed.
      int IComparer.Compare( Object x, Object y )  {
          return( (new CaseInsensitiveComparer()).Compare( y, x ) );
      }

   }

   public static void Main()  {
 
      // Creates and initializes a new Array and a new custom comparer.
      String[] myKeys = { "red", "GREEN", "YELLOW", "BLUE", "purple", "black", "orange" };
      String[] myValues = { "strawberries", "PEARS", "LIMES", "BERRIES", "grapes", "olives", "cantaloupe" };
      IComparer myComparer = new myReverserClass();
 
      // Displays the values of the Array.
      Console.WriteLine( "The Array initially contains the following values:" );
      PrintKeysAndValues( myKeys, myValues );
 
      // Sorts a section of the Array using the default comparer.
      Array.Sort( myKeys, myValues, 1, 3 );
      Console.WriteLine( "After sorting a section of the Array using the default comparer:" );
      PrintKeysAndValues( myKeys, myValues );

      // Sorts a section of the Array using the reverse case-insensitive comparer.
      Array.Sort( myKeys, myValues, 1, 3, myComparer );
      Console.WriteLine( "After sorting a section of the Array using the reverse case-insensitive comparer:" );
      PrintKeysAndValues( myKeys, myValues );

      // Sorts the entire Array using the default comparer.
      Array.Sort( myKeys, myValues );
      Console.WriteLine( "After sorting the entire Array using the default comparer:" );
      PrintKeysAndValues( myKeys, myValues );

      // Sorts the entire Array using the reverse case-insensitive comparer.
      Array.Sort( myKeys, myValues, myComparer );
      Console.WriteLine( "After sorting the entire Array using the reverse case-insensitive comparer:" );
      PrintKeysAndValues( myKeys, myValues );

   }
 
   public static void PrintKeysAndValues( String[] myKeys, String[] myValues )  {
      for ( int i = 0; i < myKeys.Length; i++ )  {
         Console.WriteLine( "   {0,-10}: {1}", myKeys[i], myValues[i] );
      }
      Console.WriteLine();
   }
}


/* 
This code produces the following output.

The Array initially contains the following values:
   red       : strawberries
   GREEN     : PEARS
   YELLOW    : LIMES
   BLUE      : BERRIES
   purple    : grapes
   black     : olives
   orange    : cantaloupe

After sorting a section of the Array using the default comparer:
   red       : strawberries
   BLUE      : BERRIES
   GREEN     : PEARS
   YELLOW    : LIMES
   purple    : grapes
   black     : olives
   orange    : cantaloupe

After sorting a section of the Array using the reverse case-insensitive comparer:
   red       : strawberries
   YELLOW    : LIMES
   GREEN     : PEARS
   BLUE      : BERRIES
   purple    : grapes
   black     : olives
   orange    : cantaloupe

After sorting the entire Array using the default comparer:
   black     : olives
   BLUE      : BERRIES
   GREEN     : PEARS
   orange    : cantaloupe
   purple    : grapes
   red       : strawberries
   YELLOW    : LIMES

After sorting the entire Array using the reverse case-insensitive comparer:
   YELLOW    : LIMES
   red       : strawberries
   purple    : grapes
   orange    : cantaloupe
   GREEN     : PEARS
   BLUE      : BERRIES
   black     : olives

*/

Imports System
Imports System.Collections

Public Class SamplesArray

   Public Class myReverserClass
      Implements IComparer

      ' Calls CaseInsensitiveComparer.Compare with the parameters reversed.
      Function Compare(x As [Object], y As [Object]) As Integer _
         Implements IComparer.Compare
         Return New CaseInsensitiveComparer().Compare(y, x)
      End Function 'IComparer.Compare

   End Class 'myReverserClass


   Public Shared Sub Main()

      ' Creates and initializes a new Array and a new custom comparer.
      Dim myKeys As [String]() =  {"red", "GREEN", "YELLOW", "BLUE", "purple", "black", "orange"}
      Dim myValues As [String]() =  {"strawberries", "PEARS", "LIMES", "BERRIES", "grapes", "olives", "cantaloupe"}
      Dim myComparer = New myReverserClass()

      ' Displays the values of the Array.
      Console.WriteLine("The Array initially contains the following values:")
      PrintKeysAndValues(myKeys, myValues)

      ' Sorts a section of the Array using the default comparer.
      Array.Sort(myKeys, myValues, 1, 3)
      Console.WriteLine("After sorting a section of the Array using the default comparer:")
      PrintKeysAndValues(myKeys, myValues)

      ' Sorts a section of the Array using the reverse case-insensitive comparer.
      Array.Sort(myKeys, myValues, 1, 3, myComparer)
      Console.WriteLine("After sorting a section of the Array using the reverse case-insensitive comparer:")
      PrintKeysAndValues(myKeys, myValues)

      ' Sorts the entire Array using the default comparer.
      Array.Sort(myKeys, myValues)
      Console.WriteLine("After sorting the entire Array using the default comparer:")
      PrintKeysAndValues(myKeys, myValues)

      ' Sorts the entire Array using the reverse case-insensitive comparer.
      Array.Sort(myKeys, myValues, myComparer)
      Console.WriteLine("After sorting the entire Array using the reverse case-insensitive comparer:")
      PrintKeysAndValues(myKeys, myValues)

   End Sub 'Main


   Public Shared Sub PrintKeysAndValues(myKeys() As [String], myValues() As [String])

      Dim i As Integer
      For i = 0 To myKeys.Length - 1
         Console.WriteLine("   {0,-10}: {1}", myKeys(i), myValues(i))
      Next i
      Console.WriteLine()

   End Sub 'PrintKeysAndValues

End Class 'SamplesArray


'This code produces the following output.
'
'The Array initially contains the following values:
'   red       : strawberries
'   GREEN     : PEARS
'   YELLOW    : LIMES
'   BLUE      : BERRIES
'   purple    : grapes
'   black     : olives
'   orange    : cantaloupe
'
'After sorting a section of the Array using the default comparer:
'   red       : strawberries
'   BLUE      : BERRIES
'   GREEN     : PEARS
'   YELLOW    : LIMES
'   purple    : grapes
'   black     : olives
'   orange    : cantaloupe
'
'After sorting a section of the Array using the reverse case-insensitive comparer:
'   red       : strawberries
'   YELLOW    : LIMES
'   GREEN     : PEARS
'   BLUE      : BERRIES
'   purple    : grapes
'   black     : olives
'   orange    : cantaloupe
'
'After sorting the entire Array using the default comparer:
'   black     : olives
'   BLUE      : BERRIES
'   GREEN     : PEARS
'   orange    : cantaloupe
'   purple    : grapes
'   red       : strawberries
'   YELLOW    : LIMES
'
'After sorting the entire Array using the reverse case-insensitive comparer:
'   YELLOW    : LIMES
'   red       : strawberries
'   purple    : grapes
'   orange    : cantaloupe
'   GREEN     : PEARS
'   BLUE      : BERRIES
'   black     : olives

Remarks

Each key in the keysArray has a corresponding item in the itemsArray. When a key is repositioned during the sorting, the corresponding item in the itemsArray is similarly repositioned. Therefore, the itemsArray is sorted according to the arrangement of the corresponding keys in the keysArray.

If comparer is null, each key within the specified range of elements in the keysArray must implement the IComparable interface to be capable of comparisons with every other key.

You can sort if there are more items than keys, but the items that have no corresponding keys will not be sorted. You cannot sort if there are more keys than items; doing this throws an ArgumentException.

If the sort is not successfully completed, the results are undefined.

The .NET Framework includes predefined IComparer implementations listed in the following table.

Implementation Description
System.Collections.CaseInsensitiveComparer Compares any two objects, but performs a case-insensitive comparison of strings.
Comparer.Default Compares any two objects by using the sorting conventions of the current culture.
Comparer.DefaultInvariant Compares any two objects by using the sorting conventions of the invariant culture.
Comparer<T>.Default Compares two objects of type T by using the type's default sort order.

You can also support custom comparisons by providing an instance of your own IComparer implementation to the comparer parameter. The example does this by defining a custom IComparer implementation that reverses the default sort order and performs case-insensitive string comparison.

This method uses the introspective sort (introsort) algorithm as follows:

  • If the partition size is fewer than 16 elements, it uses an insertion sort algorithm.

  • If the number of partitions exceeds 2 * LogN, where N is the range of the input array, it uses a Heapsort algorithm.

  • Otherwise, it uses a Quicksort algorithm.

This implementation performs an unstable sort; that is, if two elements are equal, their order might not be preserved. In contrast, a stable sort preserves the order of elements that are equal.

For arrays that are sorted by using the Heapsort and Quicksort algorithms, in the worst case, this method is an O(n log n) operation, where n is length.

Notes to Callers

The .NET Framework 4 and earlier versions used only the Quicksort algorithm. Quicksort identifies invalid comparers in some situations in which the sorting operation throws an IndexOutOfRangeException exception, and throws an ArgumentException exception to the caller. Starting with the .NET Framework 4.5, it is possible that sorting operations that previously threw ArgumentException will not throw an exception, because the insertion sort and heapsort algorithms do not detect an invalid comparer. For the most part, this applies to arrays with fewer than 16 elements.

See also

Sort(Array, Int32, Int32) Sort(Array, Int32, Int32) Sort(Array, Int32, Int32)

Sorts the elements in a range of elements in a one-dimensional Array using the IComparable implementation of each element of the Array.

public:
 static void Sort(Array ^ array, int index, int length);
public static void Sort (Array array, int index, int length);
static member Sort : Array * int * int -> unit

Parameters

array
Array Array Array Array

The one-dimensional Array to sort.

index
Int32 Int32 Int32 Int32

The starting index of the range to sort.

length
Int32 Int32 Int32 Int32

The number of elements in the range to sort.

Exceptions

index is less than the lower bound of array.

-or-

length is less than zero.

index and length do not specify a valid range in array.

Examples

The following code example shows how to sort the values in an Array using the default comparer and a custom comparer that reverses the sort order. Note that the result might vary depending on the current CultureInfo.

using namespace System;
using namespace System::Collections;

public ref class ReverseComparer : IComparer
{
public:
   // Call CaseInsensitiveComparer::Compare with the parameters reversed.
   virtual int Compare(Object^ x, Object^ y) = IComparer::Compare
   {
      return ((gcnew CaseInsensitiveComparer)->Compare(y, x));
   }
};

void DisplayValues(array<String^>^ arr)
{
   for (int i = arr->GetLowerBound(0); i <= arr->GetUpperBound(0); i++)
      Console::WriteLine( "   [{0}] : {1}", i, arr[ i ] );

   Console::WriteLine();
}

int main()
{
   // Create and initialize a new array. and a new custom comparer.
   array<String^>^ words = { "The","QUICK","BROWN","FOX","jumps",
                             "over","the","lazy","dog" };
   // Instantiate the reverse comparer.
   IComparer^ revComparer = gcnew ReverseComparer();
   
   // Display the values of the Array.
   Console::WriteLine( "The original order of elements in the array:" );
   DisplayValues(words);

   // Sort a section of the array using the default comparer.
   Array::Sort(words, 1, 3);
   Console::WriteLine( "After sorting elements 1-3 by using the default comparer:");
   DisplayValues(words);

   // Sort a section of the array using the reverse case-insensitive comparer.
   Array::Sort(words, 1, 3, revComparer);
   Console::WriteLine( "After sorting elements 1-3 by using the reverse case-insensitive comparer:");
   DisplayValues(words);

   // Sort the entire array using the default comparer.
   Array::Sort(words);
   Console::WriteLine( "After sorting the entire array by using the default comparer:");
   DisplayValues(words);

   // Sort the entire array by using the reverse case-insensitive comparer.
   Array::Sort(words, revComparer);
   Console::WriteLine( "After sorting the entire array using the reverse case-insensitive comparer:");
   DisplayValues(words);
}

/* 
This code produces the following output.

The Array initially contains the following values:
   [0] : The
   [1] : QUICK
   [2] : BROWN
   [3] : FOX
   [4] : jumps
   [5] : over
   [6] : the
   [7] : lazy
   [8] : dog

After sorting a section of the Array using the default comparer:
   [0] : The
   [1] : BROWN
   [2] : FOX
   [3] : QUICK
   [4] : jumps
   [5] : over
   [6] : the
   [7] : lazy
   [8] : dog

After sorting a section of the Array using the reverse case-insensitive comparer:
   [0] : The
   [1] : QUICK
   [2] : FOX
   [3] : BROWN
   [4] : jumps
   [5] : over
   [6] : the
   [7] : lazy
   [8] : dog

After sorting the entire Array using the default comparer:
   [0] : BROWN
   [1] : dog
   [2] : FOX
   [3] : jumps
   [4] : lazy
   [5] : over
   [6] : QUICK
   [7] : the
   [8] : The

After sorting the entire Array using the reverse case-insensitive comparer:
   [0] : the
   [1] : The
   [2] : QUICK
   [3] : over
   [4] : lazy
   [5] : jumps
   [6] : FOX
   [7] : dog
   [8] : BROWN

*/
using System;
using System.Collections;

public class ReverseComparer : IComparer  
{
   // Call CaseInsensitiveComparer.Compare with the parameters reversed.
   public int Compare(Object x, Object y)  
   {
       return (new CaseInsensitiveComparer()).Compare(y, x );
   }
}

public class Example 
{
   public static void Main()  
   {
      // Create and initialize a new array. 
      String[] words = { "The", "QUICK", "BROWN", "FOX", "jumps", 
                         "over", "the", "lazy", "dog" };
      // Instantiate the reverse comparer.
      IComparer revComparer = new ReverseComparer();
 
      // Display the values of the array.
      Console.WriteLine( "The original order of elements in the array:" );
      DisplayValues(words);
 
      // Sort a section of the array using the default comparer.
      Array.Sort(words, 1, 3);
      Console.WriteLine( "After sorting elements 1-3 by using the default comparer:");
      DisplayValues(words);

      // Sort a section of the array using the reverse case-insensitive comparer.
      Array.Sort(words, 1, 3, revComparer);
      Console.WriteLine( "After sorting elements 1-3 by using the reverse case-insensitive comparer:");
      DisplayValues(words);

      // Sort the entire array using the default comparer.
      Array.Sort(words);
      Console.WriteLine( "After sorting the entire array by using the default comparer:");
      DisplayValues(words);

      // Sort the entire array by using the reverse case-insensitive comparer.
      Array.Sort(words, revComparer);
      Console.WriteLine( "After sorting the entire array using the reverse case-insensitive comparer:");
      DisplayValues(words);
   }
 
   public static void DisplayValues(String[] arr)  
   {
      for ( int i = arr.GetLowerBound(0); i <= arr.GetUpperBound(0);
            i++ )  {
         Console.WriteLine( "   [{0}] : {1}", i, arr[i] );
      }
      Console.WriteLine();
   }
}
// The example displays the following output:
//    The original order of elements in the array:
//       [0] : The
//       [1] : QUICK
//       [2] : BROWN
//       [3] : FOX
//       [4] : jumps
//       [5] : over
//       [6] : the
//       [7] : lazy
//       [8] : dog
//    
//    After sorting elements 1-3 by using the default comparer:
//       [0] : The
//       [1] : BROWN
//       [2] : FOX
//       [3] : QUICK
//       [4] : jumps
//       [5] : over
//       [6] : the
//       [7] : lazy
//       [8] : dog
//    
//    After sorting elements 1-3 by using the reverse case-insensitive comparer:
//       [0] : The
//       [1] : QUICK
//       [2] : FOX
//       [3] : BROWN
//       [4] : jumps
//       [5] : over
//       [6] : the
//       [7] : lazy
//       [8] : dog
//    
//    After sorting the entire array by using the default comparer:
//       [0] : BROWN
//       [1] : dog
//       [2] : FOX
//       [3] : jumps
//       [4] : lazy
//       [5] : over
//       [6] : QUICK
//       [7] : the
//       [8] : The
//    
//    After sorting the entire array using the reverse case-insensitive comparer:
//       [0] : the
//       [1] : The
//       [2] : QUICK
//       [3] : over
//       [4] : lazy
//       [5] : jumps
//       [6] : FOX
//       [7] : dog
//       [8] : BROWN    
Imports System.Collections

Public Class ReverseComparer : Implements IComparer
   ' Call CaseInsensitiveComparer.Compare with the parameters reversed.
   Function Compare(x As Object, y As Object) As Integer _
            Implements IComparer.Compare
      Return New CaseInsensitiveComparer().Compare(y, x)
   End Function 
End Class

Public Module Example
   Public Sub Main()
      ' Create and initialize a new array.
      Dim words() As String =  { "The", "QUICK", "BROWN", "FOX", "jumps", 
                                 "over", "the", "lazy", "dog" }
      ' Instantiate a new custom comparer.
      Dim revComparer As New ReverseComparer()

      ' Display the values of the array.
      Console.WriteLine( "The original order of elements in the array:" )
      DisplayValues(words)

      ' Sort a section of the array using the default comparer.
      Array.Sort(words, 1, 3)
      Console.WriteLine( "After sorting elements 1-3 by using the default comparer:")
      DisplayValues(words)

      ' Sort a section of the array using the reverse case-insensitive comparer.
      Array.Sort(words, 1, 3, revComparer)
      Console.WriteLine( "After sorting elements 1-3 by using the reverse case-insensitive comparer:")
      DisplayValues(words)

      ' Sort the entire array using the default comparer.
      Array.Sort(words)
      Console.WriteLine( "After sorting the entire array by using the default comparer:")
      DisplayValues(words)

      ' Sort the entire array by using the reverse case-insensitive comparer.
      Array.Sort(words, revComparer)
      Console.WriteLine( "After sorting the entire array using the reverse case-insensitive comparer:")
      DisplayValues(words)
   End Sub 

   Public Sub DisplayValues(arr() As String)
      For i As Integer = arr.GetLowerBound(0) To arr.GetUpperBound(0)
         Console.WriteLine("   [{0}] : {1}", i, arr(i))
      Next 
      Console.WriteLine()
   End Sub 
End Module 
' The example displays the following output:
'    The original order of elements in the array:
'       [0] : The
'       [1] : QUICK
'       [2] : BROWN
'       [3] : FOX
'       [4] : jumps
'       [5] : over
'       [6] : the
'       [7] : lazy
'       [8] : dog
'    
'    After sorting elements 1-3 by using the default comparer:
'       [0] : The
'       [1] : BROWN
'       [2] : FOX
'       [3] : QUICK
'       [4] : jumps
'       [5] : over
'       [6] : the
'       [7] : lazy
'       [8] : dog
'    
'    After sorting elements 1-3 by using the reverse case-insensitive comparer:
'       [0] : The
'       [1] : QUICK
'       [2] : FOX
'       [3] : BROWN
'       [4] : jumps
'       [5] : over
'       [6] : the
'       [7] : lazy
'       [8] : dog
'    
'    After sorting the entire array by using the default comparer:
'       [0] : BROWN
'       [1] : dog
'       [2] : FOX
'       [3] : jumps
'       [4] : lazy
'       [5] : over
'       [6] : QUICK
'       [7] : the
'       [8] : The
'    
'    After sorting the entire array using the reverse case-insensitive comparer:
'       [0] : the
'       [1] : The
'       [2] : QUICK
'       [3] : over
'       [4] : lazy
'       [5] : jumps
'       [6] : FOX
'       [7] : dog
'       [8] : BROWN

Remarks

Each element within the specified range of elements in array must implement the IComparable interface to be capable of comparisons with every other element in array.

If the sort is not successfully completed, the results are undefined.

This method uses the introspective sort (introsort) algorithm as follows:

  • If the partition size is fewer than 16 elements, it uses an insertion sort algorithm.

  • If the number of partitions exceeds 2 * LogN, where N is the range of the input array, it uses a Heapsort algorithm.

  • Otherwise, it uses a Quicksort algorithm.

This implementation performs an unstable sort; that is, if two elements are equal, their order might not be preserved. In contrast, a stable sort preserves the order of elements that are equal.

For arrays that are sorted by using the Heapsort and Quicksort algorithms, in the worst case, this method is an O(n log n) operation, where n is length.

See also

Sort(Array, Array, Int32, Int32) Sort(Array, Array, Int32, Int32) Sort(Array, Array, Int32, Int32) Sort(Array, Array, Int32, Int32)

Sorts a range of elements in a pair of one-dimensional Array objects (one contains the keys and the other contains the corresponding items) based on the keys in the first Array using the IComparable implementation of each key.

public:
 static void Sort(Array ^ keys, Array ^ items, int index, int length);
public static void Sort (Array keys, Array items, int index, int length);
static member Sort : Array * Array * int * int -> unit
Public Shared Sub Sort (keys As Array, items As Array, index As Integer, length As Integer)

Parameters

keys
Array Array Array Array

The one-dimensional Array that contains the keys to sort.

items
Array Array Array Array

The one-dimensional Array that contains the items that correspond to each of the keys in the keysArray.

-or-

null to sort only the keysArray.

index
Int32 Int32 Int32 Int32

The starting index of the range to sort.

length
Int32 Int32 Int32 Int32

The number of elements in the range to sort.

Exceptions

The keysArray is multidimensional.

-or-

The itemsArray is multidimensional.

index is less than the lower bound of keys.

-or-

length is less than zero.

items is not null, and the length of keys is greater than the length of items.

-or-

index and length do not specify a valid range in the keysArray.

-or-

items is not null, and index and length do not specify a valid range in the itemsArray.

Examples

The following code example shows how to sort two associated arrays where the first array contains the keys and the second array contains the values. Sorts are done using the default comparer and a custom comparer that reverses the sort order. Note that the result might vary depending on the current CultureInfo.

using namespace System;
using namespace System::Collections;

public ref class myReverserClass: public IComparer
{
private:

   // Calls CaseInsensitiveComparer::Compare with the parameters reversed.
   virtual int Compare( Object^ x, Object^ y ) = IComparer::Compare
   {
      return ((gcnew CaseInsensitiveComparer)->Compare( y, x ));
   }
};

void PrintKeysAndValues( array<String^>^myKeys, array<String^>^myValues )
{
   for ( int i = 0; i < myKeys->Length; i++ )
   {
      Console::WriteLine( " {0, -10}: {1}", myKeys[ i ], myValues[ i ] );
   }
   Console::WriteLine();
}

int main()
{
   // Creates and initializes a new Array and a new custom comparer.
   array<String^>^myKeys = {"red","GREEN","YELLOW","BLUE","purple","black","orange"};
   array<String^>^myValues = {"strawberries","PEARS","LIMES","BERRIES","grapes","olives","cantaloupe"};
   IComparer^ myComparer = gcnew myReverserClass;

   // Displays the values of the Array.
   Console::WriteLine( "The Array initially contains the following values:" );
   PrintKeysAndValues( myKeys, myValues );

   // Sorts a section of the Array using the default comparer.
   Array::Sort( myKeys, myValues, 1, 3 );
   Console::WriteLine( "After sorting a section of the Array using the default comparer:" );

   // Sorts a section of the Array using the reverse case-insensitive comparer.
   Array::Sort( myKeys, myValues, 1, 3, myComparer );
   Console::WriteLine( "After sorting a section of the Array using the reverse case-insensitive comparer:" );
   PrintKeysAndValues( myKeys, myValues );

   // Sorts the entire Array using the default comparer.
   Array::Sort( myKeys, myValues );
   Console::WriteLine( "After sorting the entire Array using the default comparer:" );
   PrintKeysAndValues( myKeys, myValues );

   // Sorts the entire Array using the reverse case-insensitive comparer.
   Array::Sort( myKeys, myValues, myComparer );
   Console::WriteLine( "After sorting the entire Array using the reverse case-insensitive comparer:" );
   PrintKeysAndValues( myKeys, myValues );
}

/* 
This code produces the following output.

The Array initially contains the following values:
   red       : strawberries
   GREEN     : PEARS
   YELLOW    : LIMES
   BLUE      : BERRIES
   purple    : grapes
   black     : olives
   orange    : cantaloupe

After sorting a section of the Array using the default comparer:
   red       : strawberries
   BLUE      : BERRIES
   GREEN     : PEARS
   YELLOW    : LIMES
   purple    : grapes
   black     : olives
   orange    : cantaloupe

After sorting a section of the Array using the reverse case-insensitive comparer:
   red       : strawberries
   YELLOW    : LIMES
   GREEN     : PEARS
   BLUE      : BERRIES
   purple    : grapes
   black     : olives
   orange    : cantaloupe

After sorting the entire Array using the default comparer:
   black     : olives
   BLUE      : BERRIES
   GREEN     : PEARS
   orange    : cantaloupe
   purple    : grapes
   red       : strawberries
   YELLOW    : LIMES

After sorting the entire Array using the reverse case-insensitive comparer:
   YELLOW    : LIMES
   red       : strawberries
   purple    : grapes
   orange    : cantaloupe
   GREEN     : PEARS
   BLUE      : BERRIES
   black     : olives

*/
using System;
using System.Collections;

public class SamplesArray  {
 
   public class myReverserClass : IComparer  {

      // Calls CaseInsensitiveComparer.Compare with the parameters reversed.
      int IComparer.Compare( Object x, Object y )  {
          return( (new CaseInsensitiveComparer()).Compare( y, x ) );
      }

   }

   public static void Main()  {
 
      // Creates and initializes a new Array and a new custom comparer.
      String[] myKeys = { "red", "GREEN", "YELLOW", "BLUE", "purple", "black", "orange" };
      String[] myValues = { "strawberries", "PEARS", "LIMES", "BERRIES", "grapes", "olives", "cantaloupe" };
      IComparer myComparer = new myReverserClass();
 
      // Displays the values of the Array.
      Console.WriteLine( "The Array initially contains the following values:" );
      PrintKeysAndValues( myKeys, myValues );
 
      // Sorts a section of the Array using the default comparer.
      Array.Sort( myKeys, myValues, 1, 3 );
      Console.WriteLine( "After sorting a section of the Array using the default comparer:" );
      PrintKeysAndValues( myKeys, myValues );

      // Sorts a section of the Array using the reverse case-insensitive comparer.
      Array.Sort( myKeys, myValues, 1, 3, myComparer );
      Console.WriteLine( "After sorting a section of the Array using the reverse case-insensitive comparer:" );
      PrintKeysAndValues( myKeys, myValues );

      // Sorts the entire Array using the default comparer.
      Array.Sort( myKeys, myValues );
      Console.WriteLine( "After sorting the entire Array using the default comparer:" );
      PrintKeysAndValues( myKeys, myValues );

      // Sorts the entire Array using the reverse case-insensitive comparer.
      Array.Sort( myKeys, myValues, myComparer );
      Console.WriteLine( "After sorting the entire Array using the reverse case-insensitive comparer:" );
      PrintKeysAndValues( myKeys, myValues );

   }
 
   public static void PrintKeysAndValues( String[] myKeys, String[] myValues )  {
      for ( int i = 0; i < myKeys.Length; i++ )  {
         Console.WriteLine( "   {0,-10}: {1}", myKeys[i], myValues[i] );
      }
      Console.WriteLine();
   }
}


/* 
This code produces the following output.

The Array initially contains the following values:
   red       : strawberries
   GREEN     : PEARS
   YELLOW    : LIMES
   BLUE      : BERRIES
   purple    : grapes
   black     : olives
   orange    : cantaloupe

After sorting a section of the Array using the default comparer:
   red       : strawberries
   BLUE      : BERRIES
   GREEN     : PEARS
   YELLOW    : LIMES
   purple    : grapes
   black     : olives
   orange    : cantaloupe

After sorting a section of the Array using the reverse case-insensitive comparer:
   red       : strawberries
   YELLOW    : LIMES
   GREEN     : PEARS
   BLUE      : BERRIES
   purple    : grapes
   black     : olives
   orange    : cantaloupe

After sorting the entire Array using the default comparer:
   black     : olives
   BLUE      : BERRIES
   GREEN     : PEARS
   orange    : cantaloupe
   purple    : grapes
   red       : strawberries
   YELLOW    : LIMES

After sorting the entire Array using the reverse case-insensitive comparer:
   YELLOW    : LIMES
   red       : strawberries
   purple    : grapes
   orange    : cantaloupe
   GREEN     : PEARS
   BLUE      : BERRIES
   black     : olives

*/

Imports System
Imports System.Collections

Public Class SamplesArray

   Public Class myReverserClass
      Implements IComparer

      ' Calls CaseInsensitiveComparer.Compare with the parameters reversed.
      Function Compare(x As [Object], y As [Object]) As Integer _
         Implements IComparer.Compare
         Return New CaseInsensitiveComparer().Compare(y, x)
      End Function 'IComparer.Compare

   End Class 'myReverserClass


   Public Shared Sub Main()

      ' Creates and initializes a new Array and a new custom comparer.
      Dim myKeys As [String]() =  {"red", "GREEN", "YELLOW", "BLUE", "purple", "black", "orange"}
      Dim myValues As [String]() =  {"strawberries", "PEARS", "LIMES", "BERRIES", "grapes", "olives", "cantaloupe"}
      Dim myComparer = New myReverserClass()

      ' Displays the values of the Array.
      Console.WriteLine("The Array initially contains the following values:")
      PrintKeysAndValues(myKeys, myValues)

      ' Sorts a section of the Array using the default comparer.
      Array.Sort(myKeys, myValues, 1, 3)
      Console.WriteLine("After sorting a section of the Array using the default comparer:")
      PrintKeysAndValues(myKeys, myValues)

      ' Sorts a section of the Array using the reverse case-insensitive comparer.
      Array.Sort(myKeys, myValues, 1, 3, myComparer)
      Console.WriteLine("After sorting a section of the Array using the reverse case-insensitive comparer:")
      PrintKeysAndValues(myKeys, myValues)

      ' Sorts the entire Array using the default comparer.
      Array.Sort(myKeys, myValues)
      Console.WriteLine("After sorting the entire Array using the default comparer:")
      PrintKeysAndValues(myKeys, myValues)

      ' Sorts the entire Array using the reverse case-insensitive comparer.
      Array.Sort(myKeys, myValues, myComparer)
      Console.WriteLine("After sorting the entire Array using the reverse case-insensitive comparer:")
      PrintKeysAndValues(myKeys, myValues)

   End Sub 'Main


   Public Shared Sub PrintKeysAndValues(myKeys() As [String], myValues() As [String])

      Dim i As Integer
      For i = 0 To myKeys.Length - 1
         Console.WriteLine("   {0,-10}: {1}", myKeys(i), myValues(i))
      Next i
      Console.WriteLine()

   End Sub 'PrintKeysAndValues

End Class 'SamplesArray


'This code produces the following output.
'
'The Array initially contains the following values:
'   red       : strawberries
'   GREEN     : PEARS
'   YELLOW    : LIMES
'   BLUE      : BERRIES
'   purple    : grapes
'   black     : olives
'   orange    : cantaloupe
'
'After sorting a section of the Array using the default comparer:
'   red       : strawberries
'   BLUE      : BERRIES
'   GREEN     : PEARS
'   YELLOW    : LIMES
'   purple    : grapes
'   black     : olives
'   orange    : cantaloupe
'
'After sorting a section of the Array using the reverse case-insensitive comparer:
'   red       : strawberries
'   YELLOW    : LIMES
'   GREEN     : PEARS
'   BLUE      : BERRIES
'   purple    : grapes
'   black     : olives
'   orange    : cantaloupe
'
'After sorting the entire Array using the default comparer:
'   black     : olives
'   BLUE      : BERRIES
'   GREEN     : PEARS
'   orange    : cantaloupe
'   purple    : grapes
'   red       : strawberries
'   YELLOW    : LIMES
'
'After sorting the entire Array using the reverse case-insensitive comparer:
'   YELLOW    : LIMES
'   red       : strawberries
'   purple    : grapes
'   orange    : cantaloupe
'   GREEN     : PEARS
'   BLUE      : BERRIES
'   black     : olives

Remarks

Each key in the keysArray has a corresponding item in the itemsArray. When a key is repositioned during the sorting, the corresponding item in the itemsArray is similarly repositioned. Therefore, the itemsArray is sorted according to the arrangement of the corresponding keys in the keysArray.

Each key within the specified range of elements in the keysArray must implement the IComparable interface to be capable of comparisons with every other key.

You can sort if there are more items than keys, but the items that have no corresponding keys will not be sorted. You cannot sort if there are more keys than items; doing this throws an ArgumentException.

If the sort is not successfully completed, the results are undefined.

This method uses the introspective sort (introsort) algorithm as follows:

  • If the partition size is fewer than 16 elements, it uses an insertion sort algorithm.

  • If the number of partitions exceeds 2 * LogN, where N is the range of the input array, it uses a Heapsort algorithm.

  • Otherwise, it uses a Quicksort algorithm.

This implementation performs an unstable sort; that is, if two elements are equal, their order might not be preserved. In contrast, a stable sort preserves the order of elements that are equal.

For arrays that are sorted by using the Heapsort and Quicksort algorithms, in the worst case, this method is an O(n log n) operation, where n is length.

See also

Sort(Array, IComparer) Sort(Array, IComparer) Sort(Array, IComparer)

Sorts the elements in a one-dimensional Array using the specified IComparer.

public:
 static void Sort(Array ^ array, System::Collections::IComparer ^ comparer);
public static void Sort (Array array, System.Collections.IComparer comparer);
static member Sort : Array * System.Collections.IComparer -> unit

Parameters

array
Array Array Array Array

The one-dimensional array to sort.

comparer
IComparer IComparer IComparer IComparer

The implementation to use when comparing elements.

-or-

null to use the IComparable implementation of each element.

Exceptions

comparer is null, and one or more elements in array do not implement the IComparable interface.

The implementation of comparer caused an error during the sort. For example, comparer might not return 0 when comparing an item with itself.

Examples

The following example sorts the values in a string arrayby using the default comparer. It also defines a custom IComparer implementation named ReverseComparer that reverses an object's default sort order while performing a case-insensitive string comparison. Note that the output might vary depending on the current culture.

using namespace System;
using namespace System::Collections;

public ref class ReverseComparer : IComparer
{
public:
   // Call CaseInsensitiveComparer::Compare with the parameters reversed.
   virtual int Compare(Object^ x, Object^ y) = IComparer::Compare
   {
      return ((gcnew CaseInsensitiveComparer)->Compare(y, x));
   }
};

void DisplayValues(array<String^>^ arr)
{
   for (int i = arr->GetLowerBound(0); i <= arr->GetUpperBound(0); i++)
      Console::WriteLine( "   [{0}] : {1}", i, arr[ i ] );

   Console::WriteLine();
}

int main()
{
   // Create and initialize a new array. and a new custom comparer.
   array<String^>^ words = { "The","QUICK","BROWN","FOX","jumps",
                             "over","the","lazy","dog" };
   // Instantiate the reverse comparer.
   IComparer^ revComparer = gcnew ReverseComparer();
   
   // Display the values of the Array.
   Console::WriteLine( "The original order of elements in the array:" );
   DisplayValues(words);

   // Sort a section of the array using the default comparer.
   Array::Sort(words, 1, 3);
   Console::WriteLine( "After sorting elements 1-3 by using the default comparer:");
   DisplayValues(words);

   // Sort a section of the array using the reverse case-insensitive comparer.
   Array::Sort(words, 1, 3, revComparer);
   Console::WriteLine( "After sorting elements 1-3 by using the reverse case-insensitive comparer:");
   DisplayValues(words);

   // Sort the entire array using the default comparer.
   Array::Sort(words);
   Console::WriteLine( "After sorting the entire array by using the default comparer:");
   DisplayValues(words);

   // Sort the entire array by using the reverse case-insensitive comparer.
   Array::Sort(words, revComparer);
   Console::WriteLine( "After sorting the entire array using the reverse case-insensitive comparer:");
   DisplayValues(words);
}

/* 
This code produces the following output.

The Array initially contains the following values:
   [0] : The
   [1] : QUICK
   [2] : BROWN
   [3] : FOX
   [4] : jumps
   [5] : over
   [6] : the
   [7] : lazy
   [8] : dog

After sorting a section of the Array using the default comparer:
   [0] : The
   [1] : BROWN
   [2] : FOX
   [3] : QUICK
   [4] : jumps
   [5] : over
   [6] : the
   [7] : lazy
   [8] : dog

After sorting a section of the Array using the reverse case-insensitive comparer:
   [0] : The
   [1] : QUICK
   [2] : FOX
   [3] : BROWN
   [4] : jumps
   [5] : over
   [6] : the
   [7] : lazy
   [8] : dog

After sorting the entire Array using the default comparer:
   [0] : BROWN
   [1] : dog
   [2] : FOX
   [3] : jumps
   [4] : lazy
   [5] : over
   [6] : QUICK
   [7] : the
   [8] : The

After sorting the entire Array using the reverse case-insensitive comparer:
   [0] : the
   [1] : The
   [2] : QUICK
   [3] : over
   [4] : lazy
   [5] : jumps
   [6] : FOX
   [7] : dog
   [8] : BROWN

*/
using System;
using System.Collections;

public class ReverseComparer : IComparer  
{
   // Call CaseInsensitiveComparer.Compare with the parameters reversed.
   public int Compare(Object x, Object y)  
   {
       return (new CaseInsensitiveComparer()).Compare(y, x );
   }
}

public class Example 
{
   public static void Main()  
   {
      // Create and initialize a new array. 
      String[] words = { "The", "QUICK", "BROWN", "FOX", "jumps", 
                         "over", "the", "lazy", "dog" };
      // Instantiate the reverse comparer.
      IComparer revComparer = new ReverseComparer();
 
      // Display the values of the array.
      Console.WriteLine( "The original order of elements in the array:" );
      DisplayValues(words);
 
      // Sort a section of the array using the default comparer.
      Array.Sort(words, 1, 3);
      Console.WriteLine( "After sorting elements 1-3 by using the default comparer:");
      DisplayValues(words);

      // Sort a section of the array using the reverse case-insensitive comparer.
      Array.Sort(words, 1, 3, revComparer);
      Console.WriteLine( "After sorting elements 1-3 by using the reverse case-insensitive comparer:");
      DisplayValues(words);

      // Sort the entire array using the default comparer.
      Array.Sort(words);
      Console.WriteLine( "After sorting the entire array by using the default comparer:");
      DisplayValues(words);

      // Sort the entire array by using the reverse case-insensitive comparer.
      Array.Sort(words, revComparer);
      Console.WriteLine( "After sorting the entire array using the reverse case-insensitive comparer:");
      DisplayValues(words);
   }
 
   public static void DisplayValues(String[] arr)  
   {
      for ( int i = arr.GetLowerBound(0); i <= arr.GetUpperBound(0);
            i++ )  {
         Console.WriteLine( "   [{0}] : {1}", i, arr[i] );
      }
      Console.WriteLine();
   }
}
// The example displays the following output:
//    The original order of elements in the array:
//       [0] : The
//       [1] : QUICK
//       [2] : BROWN
//       [3] : FOX
//       [4] : jumps
//       [5] : over
//       [6] : the
//       [7] : lazy
//       [8] : dog
//    
//    After sorting elements 1-3 by using the default comparer:
//       [0] : The
//       [1] : BROWN
//       [2] : FOX
//       [3] : QUICK
//       [4] : jumps
//       [5] : over
//       [6] : the
//       [7] : lazy
//       [8] : dog
//    
//    After sorting elements 1-3 by using the reverse case-insensitive comparer:
//       [0] : The
//       [1] : QUICK
//       [2] : FOX
//       [3] : BROWN
//       [4] : jumps
//       [5] : over
//       [6] : the
//       [7] : lazy
//       [8] : dog
//    
//    After sorting the entire array by using the default comparer:
//       [0] : BROWN
//       [1] : dog
//       [2] : FOX
//       [3] : jumps
//       [4] : lazy
//       [5] : over
//       [6] : QUICK
//       [7] : the
//       [8] : The
//    
//    After sorting the entire array using the reverse case-insensitive comparer:
//       [0] : the
//       [1] : The
//       [2] : QUICK
//       [3] : over
//       [4] : lazy
//       [5] : jumps
//       [6] : FOX
//       [7] : dog
//       [8] : BROWN    
Imports System.Collections

Public Class ReverseComparer : Implements IComparer
   ' Call CaseInsensitiveComparer.Compare with the parameters reversed.
   Function Compare(x As Object, y As Object) As Integer _
            Implements IComparer.Compare
      Return New CaseInsensitiveComparer().Compare(y, x)
   End Function 
End Class

Public Module Example
   Public Sub Main()
      ' Create and initialize a new array.
      Dim words() As String =  { "The", "QUICK", "BROWN", "FOX", "jumps", 
                                 "over", "the", "lazy", "dog" }
      ' Instantiate a new custom comparer.
      Dim revComparer As New ReverseComparer()

      ' Display the values of the array.
      Console.WriteLine( "The original order of elements in the array:" )
      DisplayValues(words)

      ' Sort a section of the array using the default comparer.
      Array.Sort(words, 1, 3)
      Console.WriteLine( "After sorting elements 1-3 by using the default comparer:")
      DisplayValues(words)

      ' Sort a section of the array using the reverse case-insensitive comparer.
      Array.Sort(words, 1, 3, revComparer)
      Console.WriteLine( "After sorting elements 1-3 by using the reverse case-insensitive comparer:")
      DisplayValues(words)

      ' Sort the entire array using the default comparer.
      Array.Sort(words)
      Console.WriteLine( "After sorting the entire array by using the default comparer:")
      DisplayValues(words)

      ' Sort the entire array by using the reverse case-insensitive comparer.
      Array.Sort(words, revComparer)
      Console.WriteLine( "After sorting the entire array using the reverse case-insensitive comparer:")
      DisplayValues(words)
   End Sub 

   Public Sub DisplayValues(arr() As String)
      For i As Integer = arr.GetLowerBound(0) To arr.GetUpperBound(0)
         Console.WriteLine("   [{0}] : {1}", i, arr(i))
      Next 
      Console.WriteLine()
   End Sub 
End Module 
' The example displays the following output:
'    The original order of elements in the array:
'       [0] : The
'       [1] : QUICK
'       [2] : BROWN
'       [3] : FOX
'       [4] : jumps
'       [5] : over
'       [6] : the
'       [7] : lazy
'       [8] : dog
'    
'    After sorting elements 1-3 by using the default comparer:
'       [0] : The
'       [1] : BROWN
'       [2] : FOX
'       [3] : QUICK
'       [4] : jumps
'       [5] : over
'       [6] : the
'       [7] : lazy
'       [8] : dog
'    
'    After sorting elements 1-3 by using the reverse case-insensitive comparer:
'       [0] : The
'       [1] : QUICK
'       [2] : FOX
'       [3] : BROWN
'       [4] : jumps
'       [5] : over
'       [6] : the
'       [7] : lazy
'       [8] : dog
'    
'    After sorting the entire array by using the default comparer:
'       [0] : BROWN
'       [1] : dog
'       [2] : FOX
'       [3] : jumps
'       [4] : lazy
'       [5] : over
'       [6] : QUICK
'       [7] : the
'       [8] : The
'    
'    After sorting the entire array using the reverse case-insensitive comparer:
'       [0] : the
'       [1] : The
'       [2] : QUICK
'       [3] : over
'       [4] : lazy
'       [5] : jumps
'       [6] : FOX
'       [7] : dog
'       [8] : BROWN

Remarks

If comparer is null, each element of array must implement the IComparable interface to be capable of comparisons with every other element in array.

If the sort is not successfully completed, the results are undefined.

This method uses the introspective sort (introsort) algorithm as follows:

  • If the partition size is fewer than 16 elements, it uses an insertion sort algorithm.

  • If the number of partitions exceeds 2 * LogN, where N is the range of the input array, it uses a Heapsort algorithm.

  • Otherwise, it uses a Quicksort algorithm.

This implementation performs an unstable sort; that is, if two elements are equal, their order might not be preserved. In contrast, a stable sort preserves the order of elements that are equal.

For arrays that are sorted by using the Heapsort and Quicksort algorithms, in the worst case, this method is an O(n log n) operation, where n is the Length of array.

The .NET Framework includes predefined IComparer implementations listed in the following table.

Implementation Description
System.Collections.CaseInsensitiveComparer Compares any two objects, but performs a case-insensitive comparison of strings.
Comparer.Default Compares any two objects by using the sorting conventions of the current culture.
Comparer.DefaultInvariant Compares any two objects by using the sorting conventions of the invariant culture.
Comparer<T>.Default Compares two objects of type T by using the type's default sort order.

You can also support custom comparisons by providing an instance of your own IComparer implementation to the comparer parameter. The example does this by defining a ReverseComparer class that reverses the default sort order for instances of a type and performs case-insensitive string comparison.

Notes to Callers

The .NET Framework 4 and earlier versions used only the Quicksort algorithm. Quicksort identifies invalid comparers in some situations in which the sorting operation throws an IndexOutOfRangeException exception, and throws an ArgumentException exception to the caller. Starting with the .NET Framework 4.5, it is possible that sorting operations that previously threw ArgumentException will not throw an exception, because the insertion sort and heapsort algorithms do not detect an invalid comparer. For the most part, this applies to arrays with fewer than 16 elements.

See also

Sort(Array, Array, IComparer) Sort(Array, Array, IComparer) Sort(Array, Array, IComparer) Sort(Array, Array, IComparer)

Sorts a pair of one-dimensional Array objects (one contains the keys and the other contains the corresponding items) based on the keys in the first Array using the specified IComparer.

public:
 static void Sort(Array ^ keys, Array ^ items, System::Collections::IComparer ^ comparer);
public static void Sort (Array keys, Array items, System.Collections.IComparer comparer);
static member Sort : Array * Array * System.Collections.IComparer -> unit
Public Shared Sub Sort (keys As Array, items As Array, comparer As IComparer)

Parameters

keys
Array Array Array Array

The one-dimensional Array that contains the keys to sort.

items
Array Array Array Array

The one-dimensional Array that contains the items that correspond to each of the keys in the keysArray.

-or-

null to sort only the keysArray.

comparer
IComparer IComparer IComparer IComparer

The IComparer implementation to use when comparing elements.

-or-

null to use the IComparable implementation of each element.

Exceptions

The keysArray is multidimensional.

-or-

The itemsArray is multidimensional.

items is not null, and the length of keys is greater than the length of items.

-or-

The implementation of comparer caused an error during the sort. For example, comparer might not return 0 when comparing an item with itself.

comparer is null, and one or more elements in the keysArray do not implement the IComparable interface.

Examples

The following example shows how to sort two associated arrays where the first array contains the keys and the second array contains the values. Sorts are done using the default comparer and a custom comparer that reverses the sort order. Note that the result might vary depending on the current CultureInfo.

using namespace System;
using namespace System::Collections;

public ref class myReverserClass: public IComparer
{
private:

   // Calls CaseInsensitiveComparer::Compare with the parameters reversed.
   virtual int Compare( Object^ x, Object^ y ) = IComparer::Compare
   {
      return ((gcnew CaseInsensitiveComparer)->Compare( y, x ));
   }
};

void PrintKeysAndValues( array<String^>^myKeys, array<String^>^myValues )
{
   for ( int i = 0; i < myKeys->Length; i++ )
   {
      Console::WriteLine( " {0, -10}: {1}", myKeys[ i ], myValues[ i ] );
   }
   Console::WriteLine();
}

int main()
{
   // Creates and initializes a new Array and a new custom comparer.
   array<String^>^myKeys = {"red","GREEN","YELLOW","BLUE","purple","black","orange"};
   array<String^>^myValues = {"strawberries","PEARS","LIMES","BERRIES","grapes","olives","cantaloupe"};
   IComparer^ myComparer = gcnew myReverserClass;

   // Displays the values of the Array.
   Console::WriteLine( "The Array initially contains the following values:" );
   PrintKeysAndValues( myKeys, myValues );

   // Sorts a section of the Array using the default comparer.
   Array::Sort( myKeys, myValues, 1, 3 );
   Console::WriteLine( "After sorting a section of the Array using the default comparer:" );

   // Sorts a section of the Array using the reverse case-insensitive comparer.
   Array::Sort( myKeys, myValues, 1, 3, myComparer );
   Console::WriteLine( "After sorting a section of the Array using the reverse case-insensitive comparer:" );
   PrintKeysAndValues( myKeys, myValues );

   // Sorts the entire Array using the default comparer.
   Array::Sort( myKeys, myValues );
   Console::WriteLine( "After sorting the entire Array using the default comparer:" );
   PrintKeysAndValues( myKeys, myValues );

   // Sorts the entire Array using the reverse case-insensitive comparer.
   Array::Sort( myKeys, myValues, myComparer );
   Console::WriteLine( "After sorting the entire Array using the reverse case-insensitive comparer:" );
   PrintKeysAndValues( myKeys, myValues );
}

/* 
This code produces the following output.

The Array initially contains the following values:
   red       : strawberries
   GREEN     : PEARS
   YELLOW    : LIMES
   BLUE      : BERRIES
   purple    : grapes
   black     : olives
   orange    : cantaloupe

After sorting a section of the Array using the default comparer:
   red       : strawberries
   BLUE      : BERRIES
   GREEN     : PEARS
   YELLOW    : LIMES
   purple    : grapes
   black     : olives
   orange    : cantaloupe

After sorting a section of the Array using the reverse case-insensitive comparer:
   red       : strawberries
   YELLOW    : LIMES
   GREEN     : PEARS
   BLUE      : BERRIES
   purple    : grapes
   black     : olives
   orange    : cantaloupe

After sorting the entire Array using the default comparer:
   black     : olives
   BLUE      : BERRIES
   GREEN     : PEARS
   orange    : cantaloupe
   purple    : grapes
   red       : strawberries
   YELLOW    : LIMES

After sorting the entire Array using the reverse case-insensitive comparer:
   YELLOW    : LIMES
   red       : strawberries
   purple    : grapes
   orange    : cantaloupe
   GREEN     : PEARS
   BLUE      : BERRIES
   black     : olives

*/
using System;
using System.Collections;

public class SamplesArray  {
 
   public class myReverserClass : IComparer  {

      // Calls CaseInsensitiveComparer.Compare with the parameters reversed.
      int IComparer.Compare( Object x, Object y )  {
          return( (new CaseInsensitiveComparer()).Compare( y, x ) );
      }

   }

   public static void Main()  {
 
      // Creates and initializes a new Array and a new custom comparer.
      String[] myKeys = { "red", "GREEN", "YELLOW", "BLUE", "purple", "black", "orange" };
      String[] myValues = { "strawberries", "PEARS", "LIMES", "BERRIES", "grapes", "olives", "cantaloupe" };
      IComparer myComparer = new myReverserClass();
 
      // Displays the values of the Array.
      Console.WriteLine( "The Array initially contains the following values:" );
      PrintKeysAndValues( myKeys, myValues );
 
      // Sorts a section of the Array using the default comparer.
      Array.Sort( myKeys, myValues, 1, 3 );
      Console.WriteLine( "After sorting a section of the Array using the default comparer:" );
      PrintKeysAndValues( myKeys, myValues );

      // Sorts a section of the Array using the reverse case-insensitive comparer.
      Array.Sort( myKeys, myValues, 1, 3, myComparer );
      Console.WriteLine( "After sorting a section of the Array using the reverse case-insensitive comparer:" );
      PrintKeysAndValues( myKeys, myValues );

      // Sorts the entire Array using the default comparer.
      Array.Sort( myKeys, myValues );
      Console.WriteLine( "After sorting the entire Array using the default comparer:" );
      PrintKeysAndValues( myKeys, myValues );

      // Sorts the entire Array using the reverse case-insensitive comparer.
      Array.Sort( myKeys, myValues, myComparer );
      Console.WriteLine( "After sorting the entire Array using the reverse case-insensitive comparer:" );
      PrintKeysAndValues( myKeys, myValues );

   }
 
   public static void PrintKeysAndValues( String[] myKeys, String[] myValues )  {
      for ( int i = 0; i < myKeys.Length; i++ )  {
         Console.WriteLine( "   {0,-10}: {1}", myKeys[i], myValues[i] );
      }
      Console.WriteLine();
   }
}


/* 
This code produces the following output.

The Array initially contains the following values:
   red       : strawberries
   GREEN     : PEARS
   YELLOW    : LIMES
   BLUE      : BERRIES
   purple    : grapes
   black     : olives
   orange    : cantaloupe

After sorting a section of the Array using the default comparer:
   red       : strawberries
   BLUE      : BERRIES
   GREEN     : PEARS
   YELLOW    : LIMES
   purple    : grapes
   black     : olives
   orange    : cantaloupe

After sorting a section of the Array using the reverse case-insensitive comparer:
   red       : strawberries
   YELLOW    : LIMES
   GREEN     : PEARS
   BLUE      : BERRIES
   purple    : grapes
   black     : olives
   orange    : cantaloupe

After sorting the entire Array using the default comparer:
   black     : olives
   BLUE      : BERRIES
   GREEN     : PEARS
   orange    : cantaloupe
   purple    : grapes
   red       : strawberries
   YELLOW    : LIMES

After sorting the entire Array using the reverse case-insensitive comparer:
   YELLOW    : LIMES
   red       : strawberries
   purple    : grapes
   orange    : cantaloupe
   GREEN     : PEARS
   BLUE      : BERRIES
   black     : olives

*/

Imports System
Imports System.Collections

Public Class SamplesArray

   Public Class myReverserClass
      Implements IComparer

      ' Calls CaseInsensitiveComparer.Compare with the parameters reversed.
      Function Compare(x As [Object], y As [Object]) As Integer _
         Implements IComparer.Compare
         Return New CaseInsensitiveComparer().Compare(y, x)
      End Function 'IComparer.Compare

   End Class 'myReverserClass


   Public Shared Sub Main()

      ' Creates and initializes a new Array and a new custom comparer.
      Dim myKeys As [String]() =  {"red", "GREEN", "YELLOW", "BLUE", "purple", "black", "orange"}
      Dim myValues As [String]() =  {"strawberries", "PEARS", "LIMES", "BERRIES", "grapes", "olives", "cantaloupe"}
      Dim myComparer = New myReverserClass()

      ' Displays the values of the Array.
      Console.WriteLine("The Array initially contains the following values:")
      PrintKeysAndValues(myKeys, myValues)

      ' Sorts a section of the Array using the default comparer.
      Array.Sort(myKeys, myValues, 1, 3)
      Console.WriteLine("After sorting a section of the Array using the default comparer:")
      PrintKeysAndValues(myKeys, myValues)

      ' Sorts a section of the Array using the reverse case-insensitive comparer.
      Array.Sort(myKeys, myValues, 1, 3, myComparer)
      Console.WriteLine("After sorting a section of the Array using the reverse case-insensitive comparer:")
      PrintKeysAndValues(myKeys, myValues)

      ' Sorts the entire Array using the default comparer.
      Array.Sort(myKeys, myValues)
      Console.WriteLine("After sorting the entire Array using the default comparer:")
      PrintKeysAndValues(myKeys, myValues)

      ' Sorts the entire Array using the reverse case-insensitive comparer.
      Array.Sort(myKeys, myValues, myComparer)
      Console.WriteLine("After sorting the entire Array using the reverse case-insensitive comparer:")
      PrintKeysAndValues(myKeys, myValues)

   End Sub 'Main


   Public Shared Sub PrintKeysAndValues(myKeys() As [String], myValues() As [String])

      Dim i As Integer
      For i = 0 To myKeys.Length - 1
         Console.WriteLine("   {0,-10}: {1}", myKeys(i), myValues(i))
      Next i
      Console.WriteLine()

   End Sub 'PrintKeysAndValues

End Class 'SamplesArray


'This code produces the following output.
'
'The Array initially contains the following values:
'   red       : strawberries
'   GREEN     : PEARS
'   YELLOW    : LIMES
'   BLUE      : BERRIES
'   purple    : grapes
'   black     : olives
'   orange    : cantaloupe
'
'After sorting a section of the Array using the default comparer:
'   red       : strawberries
'   BLUE      : BERRIES
'   GREEN     : PEARS
'   YELLOW    : LIMES
'   purple    : grapes
'   black     : olives
'   orange    : cantaloupe
'
'After sorting a section of the Array using the reverse case-insensitive comparer:
'   red       : strawberries
'   YELLOW    : LIMES
'   GREEN     : PEARS
'   BLUE      : BERRIES
'   purple    : grapes
'   black     : olives
'   orange    : cantaloupe
'
'After sorting the entire Array using the default comparer:
'   black     : olives
'   BLUE      : BERRIES
'   GREEN     : PEARS
'   orange    : cantaloupe
'   purple    : grapes
'   red       : strawberries
'   YELLOW    : LIMES
'
'After sorting the entire Array using the reverse case-insensitive comparer:
'   YELLOW    : LIMES
'   red       : strawberries
'   purple    : grapes
'   orange    : cantaloupe
'   GREEN     : PEARS
'   BLUE      : BERRIES
'   black     : olives

Remarks

Each key in the keysArray has a corresponding item in the itemsArray. When a key is repositioned during the sorting, the corresponding item in the itemsArray is similarly repositioned. Therefore, the itemsArray is sorted according to the arrangement of the corresponding keys in the keysArray.

If comparer is null, each key in the keysArray must implement the IComparable interface to be capable of comparisons with every other key.

You can sort if there are more items than keys, but the items that have no corresponding keys will not be sorted. You cannot sort if there are more keys than items; doing this throws an ArgumentException.

If the sort is not successfully completed, the results are undefined.

The .NET Framework includes predefined IComparer implementations listed in the following table.

Implementation Description
System.Collections.CaseInsensitiveComparer Compares any two objects, but performs a case-insensitive comparison of strings.
Comparer.Default Compares any two objects by using the sorting conventions of the current culture.
Comparer.DefaultInvariant Compares any two objects by using the sorting conventions of the invariant culture.
Comparer<T>.Default Compares two objects of type T by using the type's default sort order.

You can also support custom comparisons by providing an instance of your own IComparer implementation to the comparer parameter. The example does this by defining an IComparer implementation that reverses the default sort order and performs case-insensitive string comparison.

This method uses the introspective sort (introsort) algorithm as follows:

  • If the partition size is fewer than 16 elements, it uses an insertion sort algorithm.

  • If the number of partitions exceeds 2 * LogN, where N is the range of the input array, it uses a Heapsort algorithm.

  • Otherwise, it uses a Quicksort algorithm.

This implementation performs an unstable sort; that is, if two elements are equal, their order might not be preserved. In contrast, a stable sort preserves the order of elements that are equal.

For arrays that are sorted by using the Heapsort and Quicksort algorithms, in the worst case, this method is an O(n log n) operation, where n is the Length of keys.

Notes to Callers

The .NET Framework 4 and earlier versions used only the Quicksort algorithm. Quicksort identifies invalid comparers in some situations in which the sorting operation throws an IndexOutOfRangeException exception, and throws an ArgumentException exception to the caller. Starting with the .NET Framework 4.5, it is possible that sorting operations that previouslythrew ArgumentException will not throw an exception, becausethe insertion sort and heapsort algorithms do not detect an invalid comparer. For the most part, this applies to arrays with fewer than 16 elements.

See also

Sort(Array, Array) Sort(Array, Array) Sort(Array, Array) Sort(Array, Array)

Sorts a pair of one-dimensional Array objects (one contains the keys and the other contains the corresponding items) based on the keys in the first Array using the IComparable implementation of each key.

public:
 static void Sort(Array ^ keys, Array ^ items);
public static void Sort (Array keys, Array items);
static member Sort : Array * Array -> unit
Public Shared Sub Sort (keys As Array, items As Array)

Parameters

keys
Array Array Array Array

The one-dimensional Array that contains the keys to sort.

items
Array Array Array Array

The one-dimensional Array that contains the items that correspond to each of the keys in the keysArray.

-or-

null to sort only the keysArray.

Exceptions

The keysArray is multidimensional.

-or-

The itemsArray is multidimensional.

items is not null, and the length of keys is greater than the length of items.

Examples

The following example shows how to sort two associated arrays where the first array contains the keys and the second array contains the values. Sorts are done using the default comparer and a custom comparer that reverses the sort order. Note that the result might vary depending on the current CultureInfo.

using namespace System;
using namespace System::Collections;

public ref class myReverserClass: public IComparer
{
private:

   // Calls CaseInsensitiveComparer::Compare with the parameters reversed.
   virtual int Compare( Object^ x, Object^ y ) = IComparer::Compare
   {
      return ((gcnew CaseInsensitiveComparer)->Compare( y, x ));
   }
};

void PrintKeysAndValues( array<String^>^myKeys, array<String^>^myValues )
{
   for ( int i = 0; i < myKeys->Length; i++ )
   {
      Console::WriteLine( " {0, -10}: {1}", myKeys[ i ], myValues[ i ] );
   }
   Console::WriteLine();
}

int main()
{
   // Creates and initializes a new Array and a new custom comparer.
   array<String^>^myKeys = {"red","GREEN","YELLOW","BLUE","purple","black","orange"};
   array<String^>^myValues = {"strawberries","PEARS","LIMES","BERRIES","grapes","olives","cantaloupe"};
   IComparer^ myComparer = gcnew myReverserClass;

   // Displays the values of the Array.
   Console::WriteLine( "The Array initially contains the following values:" );
   PrintKeysAndValues( myKeys, myValues );

   // Sorts a section of the Array using the default comparer.
   Array::Sort( myKeys, myValues, 1, 3 );
   Console::WriteLine( "After sorting a section of the Array using the default comparer:" );

   // Sorts a section of the Array using the reverse case-insensitive comparer.
   Array::Sort( myKeys, myValues, 1, 3, myComparer );
   Console::WriteLine( "After sorting a section of the Array using the reverse case-insensitive comparer:" );
   PrintKeysAndValues( myKeys, myValues );

   // Sorts the entire Array using the default comparer.
   Array::Sort( myKeys, myValues );
   Console::WriteLine( "After sorting the entire Array using the default comparer:" );
   PrintKeysAndValues( myKeys, myValues );

   // Sorts the entire Array using the reverse case-insensitive comparer.
   Array::Sort( myKeys, myValues, myComparer );
   Console::WriteLine( "After sorting the entire Array using the reverse case-insensitive comparer:" );
   PrintKeysAndValues( myKeys, myValues );
}

/* 
This code produces the following output.

The Array initially contains the following values:
   red       : strawberries
   GREEN     : PEARS
   YELLOW    : LIMES
   BLUE      : BERRIES
   purple    : grapes
   black     : olives
   orange    : cantaloupe

After sorting a section of the Array using the default comparer:
   red       : strawberries
   BLUE      : BERRIES
   GREEN     : PEARS
   YELLOW    : LIMES
   purple    : grapes
   black     : olives
   orange    : cantaloupe

After sorting a section of the Array using the reverse case-insensitive comparer:
   red       : strawberries
   YELLOW    : LIMES
   GREEN     : PEARS
   BLUE      : BERRIES
   purple    : grapes
   black     : olives
   orange    : cantaloupe

After sorting the entire Array using the default comparer:
   black     : olives
   BLUE      : BERRIES
   GREEN     : PEARS
   orange    : cantaloupe
   purple    : grapes
   red       : strawberries
   YELLOW    : LIMES

After sorting the entire Array using the reverse case-insensitive comparer:
   YELLOW    : LIMES
   red       : strawberries
   purple    : grapes
   orange    : cantaloupe
   GREEN     : PEARS
   BLUE      : BERRIES
   black     : olives

*/
using System;
using System.Collections;

public class SamplesArray  {
 
   public class myReverserClass : IComparer  {

      // Calls CaseInsensitiveComparer.Compare with the parameters reversed.
      int IComparer.Compare( Object x, Object y )  {
          return( (new CaseInsensitiveComparer()).Compare( y, x ) );
      }

   }

   public static void Main()  {
 
      // Creates and initializes a new Array and a new custom comparer.
      String[] myKeys = { "red", "GREEN", "YELLOW", "BLUE", "purple", "black", "orange" };
      String[] myValues = { "strawberries", "PEARS", "LIMES", "BERRIES", "grapes", "olives", "cantaloupe" };
      IComparer myComparer = new myReverserClass();
 
      // Displays the values of the Array.
      Console.WriteLine( "The Array initially contains the following values:" );
      PrintKeysAndValues( myKeys, myValues );
 
      // Sorts a section of the Array using the default comparer.
      Array.Sort( myKeys, myValues, 1, 3 );
      Console.WriteLine( "After sorting a section of the Array using the default comparer:" );
      PrintKeysAndValues( myKeys, myValues );

      // Sorts a section of the Array using the reverse case-insensitive comparer.
      Array.Sort( myKeys, myValues, 1, 3, myComparer );
      Console.WriteLine( "After sorting a section of the Array using the reverse case-insensitive comparer:" );
      PrintKeysAndValues( myKeys, myValues );

      // Sorts the entire Array using the default comparer.
      Array.Sort( myKeys, myValues );
      Console.WriteLine( "After sorting the entire Array using the default comparer:" );
      PrintKeysAndValues( myKeys, myValues );

      // Sorts the entire Array using the reverse case-insensitive comparer.
      Array.Sort( myKeys, myValues, myComparer );
      Console.WriteLine( "After sorting the entire Array using the reverse case-insensitive comparer:" );
      PrintKeysAndValues( myKeys, myValues );

   }
 
   public static void PrintKeysAndValues( String[] myKeys, String[] myValues )  {
      for ( int i = 0; i < myKeys.Length; i++ )  {
         Console.WriteLine( "   {0,-10}: {1}", myKeys[i], myValues[i] );
      }
      Console.WriteLine();
   }
}


/* 
This code produces the following output.

The Array initially contains the following values:
   red       : strawberries
   GREEN     : PEARS
   YELLOW    : LIMES
   BLUE      : BERRIES
   purple    : grapes
   black     : olives
   orange    : cantaloupe

After sorting a section of the Array using the default comparer:
   red       : strawberries
   BLUE      : BERRIES
   GREEN     : PEARS
   YELLOW    : LIMES
   purple    : grapes
   black     : olives
   orange    : cantaloupe

After sorting a section of the Array using the reverse case-insensitive comparer:
   red       : strawberries
   YELLOW    : LIMES
   GREEN     : PEARS
   BLUE      : BERRIES
   purple    : grapes
   black     : olives
   orange    : cantaloupe

After sorting the entire Array using the default comparer:
   black     : olives
   BLUE      : BERRIES
   GREEN     : PEARS
   orange    : cantaloupe
   purple    : grapes
   red       : strawberries
   YELLOW    : LIMES

After sorting the entire Array using the reverse case-insensitive comparer:
   YELLOW    : LIMES
   red       : strawberries
   purple    : grapes
   orange    : cantaloupe
   GREEN     : PEARS
   BLUE      : BERRIES
   black     : olives

*/

Imports System
Imports System.Collections

Public Class SamplesArray

   Public Class myReverserClass
      Implements IComparer

      ' Calls CaseInsensitiveComparer.Compare with the parameters reversed.
      Function Compare(x As [Object], y As [Object]) As Integer _
         Implements IComparer.Compare
         Return New CaseInsensitiveComparer().Compare(y, x)
      End Function 'IComparer.Compare

   End Class 'myReverserClass


   Public Shared Sub Main()

      ' Creates and initializes a new Array and a new custom comparer.
      Dim myKeys As [String]() =  {"red", "GREEN", "YELLOW", "BLUE", "purple", "black", "orange"}
      Dim myValues As [String]() =  {"strawberries", "PEARS", "LIMES", "BERRIES", "grapes", "olives", "cantaloupe"}
      Dim myComparer = New myReverserClass()

      ' Displays the values of the Array.
      Console.WriteLine("The Array initially contains the following values:")
      PrintKeysAndValues(myKeys, myValues)

      ' Sorts a section of the Array using the default comparer.
      Array.Sort(myKeys, myValues, 1, 3)
      Console.WriteLine("After sorting a section of the Array using the default comparer:")
      PrintKeysAndValues(myKeys, myValues)

      ' Sorts a section of the Array using the reverse case-insensitive comparer.
      Array.Sort(myKeys, myValues, 1, 3, myComparer)
      Console.WriteLine("After sorting a section of the Array using the reverse case-insensitive comparer:")
      PrintKeysAndValues(myKeys, myValues)

      ' Sorts the entire Array using the default comparer.
      Array.Sort(myKeys, myValues)
      Console.WriteLine("After sorting the entire Array using the default comparer:")
      PrintKeysAndValues(myKeys, myValues)

      ' Sorts the entire Array using the reverse case-insensitive comparer.
      Array.Sort(myKeys, myValues, myComparer)
      Console.WriteLine("After sorting the entire Array using the reverse case-insensitive comparer:")
      PrintKeysAndValues(myKeys, myValues)

   End Sub 'Main


   Public Shared Sub PrintKeysAndValues(myKeys() As [String], myValues() As [String])

      Dim i As Integer
      For i = 0 To myKeys.Length - 1
         Console.WriteLine("   {0,-10}: {1}", myKeys(i), myValues(i))
      Next i
      Console.WriteLine()

   End Sub 'PrintKeysAndValues

End Class 'SamplesArray


'This code produces the following output.
'
'The Array initially contains the following values:
'   red       : strawberries
'   GREEN     : PEARS
'   YELLOW    : LIMES
'   BLUE      : BERRIES
'   purple    : grapes
'   black     : olives
'   orange    : cantaloupe
'
'After sorting a section of the Array using the default comparer:
'   red       : strawberries
'   BLUE      : BERRIES
'   GREEN     : PEARS
'   YELLOW    : LIMES
'   purple    : grapes
'   black     : olives
'   orange    : cantaloupe
'
'After sorting a section of the Array using the reverse case-insensitive comparer:
'   red       : strawberries
'   YELLOW    : LIMES
'   GREEN     : PEARS
'   BLUE      : BERRIES
'   purple    : grapes
'   black     : olives
'   orange    : cantaloupe
'
'After sorting the entire Array using the default comparer:
'   black     : olives
'   BLUE      : BERRIES
'   GREEN     : PEARS
'   orange    : cantaloupe
'   purple    : grapes
'   red       : strawberries
'   YELLOW    : LIMES
'
'After sorting the entire Array using the reverse case-insensitive comparer:
'   YELLOW    : LIMES
'   red       : strawberries
'   purple    : grapes
'   orange    : cantaloupe
'   GREEN     : PEARS
'   BLUE      : BERRIES
'   black     : olives

Remarks

Each key in the keysArray has a corresponding item in the itemsArray. When a key is repositioned during the sorting, the corresponding item in the itemsArray is similarly repositioned. Therefore, the itemsArray is sorted according to the arrangement of the corresponding keys in the keysArray.

Each key in the keysArray must implement the IComparable interface to be capable of comparisons with every other key.

You can sort if there are more items than keys, but the items that have no corresponding keys will not be sorted. You cannot sort if there are more keys than items; doing this throws an ArgumentException.

If the sort is not successfully completed, the results are undefined.

This method uses the introspective sort (introsort) algorithm as follows:

  • If the partition size is fewer than 16 elements, it uses an insertion sort algorithm.

  • If the number of partitions exceeds 2 * LogN, where N is the range of the input array, it uses a Heapsort algorithm.

  • Otherwise, it uses a Quicksort algorithm.

This implementation performs an unstable sort; that is, if two elements are equal, their order might not be preserved. In contrast, a stable sort preserves the order of elements that are equal.

For arrays that are sorted by using the Heapsort and Quicksort algorithms, in the worst case, this method is an O(n log n) operation, where n is the Length of keys.

See also

Sort(Array) Sort(Array) Sort(Array)

Sorts the elements in an entire one-dimensional Array using the IComparable implementation of each element of the Array.

public:
 static void Sort(Array ^ array);
public static void Sort (Array array);
static member Sort : Array -> unit

Parameters

array
Array Array Array Array

The one-dimensional Array to sort.

Exceptions

Examples

The following code example shows how to sort the values in an Array using the default comparer and a custom comparer that reverses the sort order. Note that the result might vary depending on the current CultureInfo.

using namespace System;
using namespace System::Collections;

public ref class ReverseComparer : IComparer
{
public:
   // Call CaseInsensitiveComparer::Compare with the parameters reversed.
   virtual int Compare(Object^ x, Object^ y) = IComparer::Compare
   {
      return ((gcnew CaseInsensitiveComparer)->Compare(y, x));
   }
};

void DisplayValues(array<String^>^ arr)
{
   for (int i = arr->GetLowerBound(0); i <= arr->GetUpperBound(0); i++)
      Console::WriteLine( "   [{0}] : {1}", i, arr[ i ] );

   Console::WriteLine();
}

int main()
{
   // Create and initialize a new array. and a new custom comparer.
   array<String^>^ words = { "The","QUICK","BROWN","FOX","jumps",
                             "over","the","lazy","dog" };
   // Instantiate the reverse comparer.
   IComparer^ revComparer = gcnew ReverseComparer();
   
   // Display the values of the Array.
   Console::WriteLine( "The original order of elements in the array:" );
   DisplayValues(words);

   // Sort a section of the array using the default comparer.
   Array::Sort(words, 1, 3);
   Console::WriteLine( "After sorting elements 1-3 by using the default comparer:");
   DisplayValues(words);

   // Sort a section of the array using the reverse case-insensitive comparer.
   Array::Sort(words, 1, 3, revComparer);
   Console::WriteLine( "After sorting elements 1-3 by using the reverse case-insensitive comparer:");
   DisplayValues(words);

   // Sort the entire array using the default comparer.
   Array::Sort(words);
   Console::WriteLine( "After sorting the entire array by using the default comparer:");
   DisplayValues(words);

   // Sort the entire array by using the reverse case-insensitive comparer.
   Array::Sort(words, revComparer);
   Console::WriteLine( "After sorting the entire array using the reverse case-insensitive comparer:");
   DisplayValues(words);
}

/* 
This code produces the following output.

The Array initially contains the following values:
   [0] : The
   [1] : QUICK
   [2] : BROWN
   [3] : FOX
   [4] : jumps
   [5] : over
   [6] : the
   [7] : lazy
   [8] : dog

After sorting a section of the Array using the default comparer:
   [0] : The
   [1] : BROWN
   [2] : FOX
   [3] : QUICK
   [4] : jumps
   [5] : over
   [6] : the
   [7] : lazy
   [8] : dog

After sorting a section of the Array using the reverse case-insensitive comparer:
   [0] : The
   [1] : QUICK
   [2] : FOX
   [3] : BROWN
   [4] : jumps
   [5] : over
   [6] : the
   [7] : lazy
   [8] : dog

After sorting the entire Array using the default comparer:
   [0] : BROWN
   [1] : dog
   [2] : FOX
   [3] : jumps
   [4] : lazy
   [5] : over
   [6] : QUICK
   [7] : the
   [8] : The

After sorting the entire Array using the reverse case-insensitive comparer:
   [0] : the
   [1] : The
   [2] : QUICK
   [3] : over
   [4] : lazy
   [5] : jumps
   [6] : FOX
   [7] : dog
   [8] : BROWN

*/
using System;
using System.Collections;

public class ReverseComparer : IComparer  
{
   // Call CaseInsensitiveComparer.Compare with the parameters reversed.
   public int Compare(Object x, Object y)  
   {
       return (new CaseInsensitiveComparer()).Compare(y, x );
   }
}

public class Example 
{
   public static void Main()  
   {
      // Create and initialize a new array. 
      String[] words = { "The", "QUICK", "BROWN", "FOX", "jumps", 
                         "over", "the", "lazy", "dog" };
      // Instantiate the reverse comparer.
      IComparer revComparer = new ReverseComparer();
 
      // Display the values of the array.
      Console.WriteLine( "The original order of elements in the array:" );
      DisplayValues(words);
 
      // Sort a section of the array using the default comparer.
      Array.Sort(words, 1, 3);
      Console.WriteLine( "After sorting elements 1-3 by using the default comparer:");
      DisplayValues(words);

      // Sort a section of the array using the reverse case-insensitive comparer.
      Array.Sort(words, 1, 3, revComparer);
      Console.WriteLine( "After sorting elements 1-3 by using the reverse case-insensitive comparer:");
      DisplayValues(words);

      // Sort the entire array using the default comparer.
      Array.Sort(words);
      Console.WriteLine( "After sorting the entire array by using the default comparer:");
      DisplayValues(words);

      // Sort the entire array by using the reverse case-insensitive comparer.
      Array.Sort(words, revComparer);
      Console.WriteLine( "After sorting the entire array using the reverse case-insensitive comparer:");
      DisplayValues(words);
   }
 
   public static void DisplayValues(String[] arr)  
   {
      for ( int i = arr.GetLowerBound(0); i <= arr.GetUpperBound(0);
            i++ )  {
         Console.WriteLine( "   [{0}] : {1}", i, arr[i] );
      }
      Console.WriteLine();
   }
}
// The example displays the following output:
//    The original order of elements in the array:
//       [0] : The
//       [1] : QUICK
//       [2] : BROWN
//       [3] : FOX
//       [4] : jumps
//       [5] : over
//       [6] : the
//       [7] : lazy
//       [8] : dog
//    
//    After sorting elements 1-3 by using the default comparer:
//       [0] : The
//       [1] : BROWN
//       [2] : FOX
//       [3] : QUICK
//       [4] : jumps
//       [5] : over
//       [6] : the
//       [7] : lazy
//       [8] : dog
//    
//    After sorting elements 1-3 by using the reverse case-insensitive comparer:
//       [0] : The
//       [1] : QUICK
//       [2] : FOX
//       [3] : BROWN
//       [4] : jumps
//       [5] : over
//       [6] : the
//       [7] : lazy
//       [8] : dog
//    
//    After sorting the entire array by using the default comparer:
//       [0] : BROWN
//       [1] : dog
//       [2] : FOX
//       [3] : jumps
//       [4] : lazy
//       [5] : over
//       [6] : QUICK
//       [7] : the
//       [8] : The
//    
//    After sorting the entire array using the reverse case-insensitive comparer:
//       [0] : the
//       [1] : The
//       [2] : QUICK
//       [3] : over
//       [4] : lazy
//       [5] : jumps
//       [6] : FOX
//       [7] : dog
//       [8] : BROWN    
Imports System.Collections

Public Class ReverseComparer : Implements IComparer
   ' Call CaseInsensitiveComparer.Compare with the parameters reversed.
   Function Compare(x As Object, y As Object) As Integer _
            Implements IComparer.Compare
      Return New CaseInsensitiveComparer().Compare(y, x)
   End Function 
End Class

Public Module Example
   Public Sub Main()
      ' Create and initialize a new array.
      Dim words() As String =  { "The", "QUICK", "BROWN", "FOX", "jumps", 
                                 "over", "the", "lazy", "dog" }
      ' Instantiate a new custom comparer.
      Dim revComparer As New ReverseComparer()

      ' Display the values of the array.
      Console.WriteLine( "The original order of elements in the array:" )
      DisplayValues(words)

      ' Sort a section of the array using the default comparer.
      Array.Sort(words, 1, 3)
      Console.WriteLine( "After sorting elements 1-3 by using the default comparer:")
      DisplayValues(words)

      ' Sort a section of the array using the reverse case-insensitive comparer.
      Array.Sort(words, 1, 3, revComparer)
      Console.WriteLine( "After sorting elements 1-3 by using the reverse case-insensitive comparer:")
      DisplayValues(words)

      ' Sort the entire array using the default comparer.
      Array.Sort(words)
      Console.WriteLine( "After sorting the entire array by using the default comparer:")
      DisplayValues(words)

      ' Sort the entire array by using the reverse case-insensitive comparer.
      Array.Sort(words, revComparer)
      Console.WriteLine( "After sorting the entire array using the reverse case-insensitive comparer:")
      DisplayValues(words)
   End Sub 

   Public Sub DisplayValues(arr() As String)
      For i As Integer = arr.GetLowerBound(0) To arr.GetUpperBound(0)
         Console.WriteLine("   [{0}] : {1}", i, arr(i))
      Next 
      Console.WriteLine()
   End Sub 
End Module 
' The example displays the following output:
'    The original order of elements in the array:
'       [0] : The
'       [1] : QUICK
'       [2] : BROWN
'       [3] : FOX
'       [4] : jumps
'       [5] : over
'       [6] : the
'       [7] : lazy
'       [8] : dog
'    
'    After sorting elements 1-3 by using the default comparer:
'       [0] : The
'       [1] : BROWN
'       [2] : FOX
'       [3] : QUICK
'       [4] : jumps
'       [5] : over
'       [6] : the
'       [7] : lazy
'       [8] : dog
'    
'    After sorting elements 1-3 by using the reverse case-insensitive comparer:
'       [0] : The
'       [1] : QUICK
'       [2] : FOX
'       [3] : BROWN
'       [4] : jumps
'       [5] : over
'       [6] : the
'       [7] : lazy
'       [8] : dog
'    
'    After sorting the entire array by using the default comparer:
'       [0] : BROWN
'       [1] : dog
'       [2] : FOX
'       [3] : jumps
'       [4] : lazy
'       [5] : over
'       [6] : QUICK
'       [7] : the
'       [8] : The
'    
'    After sorting the entire array using the reverse case-insensitive comparer:
'       [0] : the
'       [1] : The
'       [2] : QUICK
'       [3] : over
'       [4] : lazy
'       [5] : jumps
'       [6] : FOX
'       [7] : dog
'       [8] : BROWN

Remarks

Each element of array must implement the IComparable interface to be capable of comparisons with every other element in array.

If the sort is not successfully completed, the results are undefined.

This method uses the introspective sort (introsort) algorithm as follows:

  • If the partition size is fewer than 16 elements, it uses an insertion sort algorithm.

  • If the number of partitions exceeds 2 * LogN, where N is the range of the input array, it uses a Heapsort algorithm.

  • Otherwise, it uses a Quicksort algorithm.

This implementation performs an unstable sort; that is, if two elements are equal, their order might not be preserved. In contrast, a stable sort preserves the order of elements that are equal.

For arrays that are sorted by using the Heapsort and Quicksort algorithms, in the worst case, this method is an O(n log n) operation, where n is the Length of array.

See also

Sort<T>(T[]) Sort<T>(T[]) Sort<T>(T[]) Sort<T>(T[])

Sorts the elements in an entire Array using the IComparable<T> generic interface implementation of each element of the Array.

public:
generic <typename T>
 static void Sort(cli::array <T> ^ array);
public static void Sort<T> (T[] array);
static member Sort : 'T[] -> unit
Public Shared Sub Sort(Of T) (array As T())

Type Parameters

T

The type of the elements of the array.

Parameters

array
T[]

The one-dimensional, zero-based Array to sort.

Exceptions

One or more elements in array do not implement the IComparable<T> generic interface.

Examples

The following code example demonstrates the Sort<T>(T[]) generic method overload and the BinarySearch<T>(T[], T) generic method overload. An array of strings is created, in no particular order.

The array is displayed, sorted, and displayed again.

Note

The calls to the Sort and BinarySearch generic methods do not look any different from calls to their nongeneric counterparts, because Visual Basic, C#, and C++ infer the type of the generic type parameter from the type of the first argument. If you use the Ildasm.exe (IL Disassembler) to examine the Microsoft intermediate language (MSIL), you can see that the generic methods are being called.

The BinarySearch<T>(T[], T) generic method overload is then used to search for two strings, one that is not in the array and one that is. The array and the return value of the BinarySearch method are passed to the ShowWhere generic method, which displays the index value if the string is found, and otherwise the elements the search string would fall between if it were in the array. The index is negative if the string is not n the array, so the ShowWhere method takes the bitwise complement (the ~ operator in C# and Visual C++, Xor -1 in Visual Basic) to obtain the index of the first element in the list that is larger than the search string.

using namespace System;
using namespace System::Collections::Generic;

generic<typename T> void ShowWhere(array<T>^ arr, int index)
{
    if (index<0)
    {
        // If the index is negative, it represents the bitwise
        // complement of the next larger element in the array.
        //
        index = ~index;

        Console::Write("Not found. Sorts between: ");

        if (index == 0)
            Console::Write("beginning of array and ");
        else
            Console::Write("{0} and ", arr[index-1]);

        if (index == arr->Length)
            Console::WriteLine("end of array.");
        else
            Console::WriteLine("{0}.", arr[index]);
    }
    else
    {
        Console::WriteLine("Found at index {0}.", index);
    }
};

void main()
{
    array<String^>^ dinosaurs = {"Pachycephalosaurus", 
                                 "Amargasaurus", 
                                 "Tyrannosaurus", 
                                 "Mamenchisaurus", 
                                 "Deinonychus", 
                                 "Edmontosaurus"};

    Console::WriteLine();
    for each(String^ dinosaur in dinosaurs)
    {
        Console::WriteLine(dinosaur);
    }

    Console::WriteLine("\nSort");
    Array::Sort(dinosaurs);

    Console::WriteLine();
    for each(String^ dinosaur in dinosaurs)
    {
        Console::WriteLine(dinosaur);
    }

    Console::WriteLine("\nBinarySearch for 'Coelophysis':");
    int index = Array::BinarySearch(dinosaurs, "Coelophysis");
    ShowWhere(dinosaurs, index);

    Console::WriteLine("\nBinarySearch for 'Tyrannosaurus':");
    index = Array::BinarySearch(dinosaurs, "Tyrannosaurus");
    ShowWhere(dinosaurs, index);
}

/* This code example produces the following output:

Pachycephalosaurus
Amargasaurus
Tyrannosaurus
Mamenchisaurus
Deinonychus
Edmontosaurus

Sort

Amargasaurus
Deinonychus
Edmontosaurus
Mamenchisaurus
Pachycephalosaurus
Tyrannosaurus

BinarySearch for 'Coelophysis':
Not found. Sorts between: Amargasaurus and Deinonychus.

BinarySearch for 'Tyrannosaurus':
Found at index 5.
 */
using System;
using System.Collections.Generic;

public class Example
{
    public static void Main()
    {
        string[] dinosaurs = {"Pachycephalosaurus", 
                              "Amargasaurus", 
                              "Tyrannosaurus", 
                              "Mamenchisaurus", 
                              "Deinonychus", 
                              "Edmontosaurus"};

        Console.WriteLine();
        foreach( string dinosaur in dinosaurs )
        {
            Console.WriteLine(dinosaur);
        }

        Console.WriteLine("\nSort");
        Array.Sort(dinosaurs);

        Console.WriteLine();
        foreach( string dinosaur in dinosaurs )
        {
            Console.WriteLine(dinosaur);
        }

        Console.WriteLine("\nBinarySearch for 'Coelophysis':");
        int index = Array.BinarySearch(dinosaurs, "Coelophysis");
        ShowWhere(dinosaurs, index);

        Console.WriteLine("\nBinarySearch for 'Tyrannosaurus':");
        index = Array.BinarySearch(dinosaurs, "Tyrannosaurus");
        ShowWhere(dinosaurs, index);
    }

    private static void ShowWhere<T>(T[] array, int index)
    {
        if (index<0)
        {
            // If the index is negative, it represents the bitwise
            // complement of the next larger element in the array.
            //
            index = ~index;

            Console.Write("Not found. Sorts between: ");

            if (index == 0)
                Console.Write("beginning of array and ");
            else
                Console.Write("{0} and ", array[index-1]);

            if (index == array.Length)
                Console.WriteLine("end of array.");
            else
                Console.WriteLine("{0}.", array[index]);
        }
        else
        {
            Console.WriteLine("Found at index {0}.", index);
        }
    }
}

/* This code example produces the following output:

Pachycephalosaurus
Amargasaurus
Tyrannosaurus
Mamenchisaurus
Deinonychus
Edmontosaurus

Sort

Amargasaurus
Deinonychus
Edmontosaurus
Mamenchisaurus
Pachycephalosaurus
Tyrannosaurus

BinarySearch for 'Coelophysis':
Not found. Sorts between: Amargasaurus and Deinonychus.

BinarySearch for 'Tyrannosaurus':
Found at index 5.
 */
Imports System
Imports System.Collections.Generic

Public Class Example

    Public Shared Sub Main()

        Dim dinosaurs() As String = { _
            "Pachycephalosaurus", _
            "Amargasaurus", _
            "Tyrannosaurus", _
            "Mamenchisaurus", _
            "Deinonychus", _
            "Edmontosaurus"  }

        Console.WriteLine()
        For Each dinosaur As String In dinosaurs
            Console.WriteLine(dinosaur)
        Next

        Console.WriteLine(vbLf & "Sort")
        Array.Sort(dinosaurs)

        Console.WriteLine()
        For Each dinosaur As String In dinosaurs
            Console.WriteLine(dinosaur)
        Next

        Console.WriteLine(vbLf & _
            "BinarySearch for 'Coelophysis':")
        Dim index As Integer = _
            Array.BinarySearch(dinosaurs, "Coelophysis")
        ShowWhere(dinosaurs, index)

        Console.WriteLine(vbLf & _
            "BinarySearch for 'Tyrannosaurus':")
        index = Array.BinarySearch(dinosaurs, "Tyrannosaurus")
        ShowWhere(dinosaurs, index)

    End Sub

    Private Shared Sub ShowWhere(Of T) _
        (ByVal array() As T, ByVal index As Integer) 

        If index < 0 Then
            ' If the index is negative, it represents the bitwise
            ' complement of the next larger element in the array.
            '
            index = index Xor -1

            Console.Write("Not found. Sorts between: ")

            If index = 0 Then
                Console.Write("beginning of array and ")
            Else
                Console.Write("{0} and ", array(index - 1))
            End If 

            If index = array.Length Then
                Console.WriteLine("end of array.")
            Else
                Console.WriteLine("{0}.", array(index))
            End If 
        Else
            Console.WriteLine("Found at index {0}.", index)
        End If

    End Sub

End Class

' This code example produces the following output:
'
'Pachycephalosaurus
'Amargasaurus
'Tyrannosaurus
'Mamenchisaurus
'Deinonychus
'Edmontosaurus
'
'Sort
'
'Amargasaurus
'Deinonychus
'Edmontosaurus
'Mamenchisaurus
'Pachycephalosaurus
'Tyrannosaurus
'
'BinarySearch for 'Coelophysis':
'Not found. Sorts between: Amargasaurus and Deinonychus.
'
'BinarySearch for 'Tyrannosaurus':
'Found at index 5.

Remarks

Each element of array must implement the IComparable<T> generic interface to be capable of comparisons with every other element in array.

If the sort is not successfully completed, the results are undefined.

This method uses the introspective sort (introsort) algorithm as follows:

  • If the partition size is fewer than 16 elements, it uses an insertion sort algorithm.

  • If the number of partitions exceeds 2 * LogN, where N is the range of the input array, it uses a Heapsort algorithm.

  • Otherwise, it uses a Quicksort algorithm.

This implementation performs an unstable sort; that is, if two elements are equal, their order might not be preserved. In contrast, a stable sort preserves the order of elements that are equal.

For arrays that are sorted by using the Heapsort and Quicksort algorithms, in the worst case, this method is an O(n log n) operation, where n is the Length of array.

See also

Sort<T>(T[], IComparer<T>) Sort<T>(T[], IComparer<T>) Sort<T>(T[], IComparer<T>) Sort<T>(T[], IComparer<T>)

Sorts the elements in an Array using the specified IComparer<T> generic interface.

public:
generic <typename T>
 static void Sort(cli::array <T> ^ array, System::Collections::Generic::IComparer<T> ^ comparer);
public static void Sort<T> (T[] array, System.Collections.Generic.IComparer<T> comparer);
static member Sort : 'T[] * System.Collections.Generic.IComparer<'T> -> unit
Public Shared Sub Sort(Of T) (array As T(), comparer As IComparer(Of T))

Type Parameters

T

The type of the elements of the array.

Parameters

array
T[]

The one-dimensional, zero-base Array to sort

comparer
IComparer<T> IComparer<T> IComparer<T> IComparer<T>

The IComparer<T> generic interface implementation to use when comparing elements, or null to use the IComparable<T> generic interface implementation of each element.

Exceptions

comparer is null, and one or more elements in array do not implement the IComparable<T> generic interface.

The implementation of comparer caused an error during the sort. For example, comparer might not return 0 when comparing an item with itself.

Examples

The following code example demonstrates the Sort<T>(T[], IComparer<T>) generic method overload and the BinarySearch<T>(T[], T, IComparer<T>) generic method overload.

The code example defines an alternative comparer for strings, named ReverseCompare, which implements the IComparer<string> (IComparer(Of String) in Visual Basic, IComparer<String^> in Visual C++) generic interface. The comparer calls the CompareTo(String) method, reversing the order of the comparands so that the strings sort high-to-low instead of low-to-high.

The array is displayed, sorted, and displayed again. Arrays must be sorted in order to use the BinarySearch method.

Note

The calls to the Sort<T>(T[], IComparer<T>) and BinarySearch<T>(T[], T, IComparer<T>) generic methods do not look any different from calls to their nongeneric counterparts, because Visual Basic, C#, and C++ infer the type of the generic type parameter from the type of the first argument. If you use the Ildasm.exe (IL Disassembler) to examine the Microsoft intermediate language (MSIL), you can see that the generic methods are being called.

The BinarySearch<T>(T[], T, IComparer<T>) generic method overload is then used to search for two strings, one that is not in the array and one that is. The array and the return value of the BinarySearch<T>(T[], T, IComparer<T>) method are passed to the ShowWhere generic method, which displays the index value if the string is found, and otherwise the elements the search string would fall between if it were in the array. The index is negative if the string is not n the array, so the ShowWhere method takes the bitwise complement (the ~ operator in C# and Visual C++, Xor -1 in Visual Basic) to obtain the index of the first element in the list that is larger than the search string.

using namespace System;
using namespace System::Collections::Generic;

public ref class ReverseComparer: IComparer<String^>
{
public:
    virtual int Compare(String^ x, String^ y)
    {
        // Compare y and x in reverse order.
        return y->CompareTo(x);
    }
};

generic<typename T> void ShowWhere(array<T>^ arr, int index)
{
    if (index<0)
    {
        // If the index is negative, it represents the bitwise
        // complement of the next larger element in the array.
        //
        index = ~index;

        Console::Write("Not found. Sorts between: ");

        if (index == 0)
            Console::Write("beginning of array and ");
        else
            Console::Write("{0} and ", arr[index-1]);

        if (index == arr->Length)
            Console::WriteLine("end of array.");
        else
            Console::WriteLine("{0}.", arr[index]);
    }
    else
    {
        Console::WriteLine("Found at index {0}.", index);
    }
};

void main()
{
    array<String^>^ dinosaurs = {"Pachycephalosaurus", 
                                 "Amargasaurus", 
                                 "Tyrannosaurus", 
                                 "Mamenchisaurus", 
                                 "Deinonychus", 
                                 "Edmontosaurus"};

    Console::WriteLine();
    for each(String^ dinosaur in dinosaurs)
    {
        Console::WriteLine(dinosaur);
    }

    ReverseComparer^ rc = gcnew ReverseComparer();

    Console::WriteLine("\nSort");
    Array::Sort(dinosaurs, rc);

    Console::WriteLine();
    for each(String^ dinosaur in dinosaurs)
    {
        Console::WriteLine(dinosaur);
    }

    Console::WriteLine("\nBinarySearch for 'Coelophysis':");
    int index = Array::BinarySearch(dinosaurs, "Coelophysis", rc);
    ShowWhere(dinosaurs, index);

    Console::WriteLine("\nBinarySearch for 'Tyrannosaurus':");
    index = Array::BinarySearch(dinosaurs, "Tyrannosaurus", rc);
    ShowWhere(dinosaurs, index);
}

/* This code example produces the following output:

Pachycephalosaurus
Amargasaurus
Tyrannosaurus
Mamenchisaurus
Deinonychus
Edmontosaurus

Sort

Tyrannosaurus
Pachycephalosaurus
Mamenchisaurus
Edmontosaurus
Deinonychus
Amargasaurus

BinarySearch for 'Coelophysis':
Not found. Sorts between: Deinonychus and Amargasaurus.

BinarySearch for 'Tyrannosaurus':
Found at index 0.
 */
using System;
using System.Collections.Generic;

public class ReverseComparer: IComparer<string>
{
    public int Compare(string x, string y)
    {
        // Compare y and x in reverse order.
        return y.CompareTo(x);
    }
}

public class Example
{
    public static void Main()
    {
        string[] dinosaurs = {"Pachycephalosaurus", 
                              "Amargasaurus", 
                              "Tyrannosaurus", 
                              "Mamenchisaurus", 
                              "Deinonychus", 
                              "Edmontosaurus"};

        Console.WriteLine();
        foreach( string dinosaur in dinosaurs )
        {
            Console.WriteLine(dinosaur);
        }

        ReverseComparer rc = new ReverseComparer();

        Console.WriteLine("\nSort");
        Array.Sort(dinosaurs, rc);

        Console.WriteLine();
        foreach( string dinosaur in dinosaurs )
        {
            Console.WriteLine(dinosaur);
        }

        Console.WriteLine("\nBinarySearch for 'Coelophysis':");
        int index = Array.BinarySearch(dinosaurs, "Coelophysis", rc);
        ShowWhere(dinosaurs, index);

        Console.WriteLine("\nBinarySearch for 'Tyrannosaurus':");
        index = Array.BinarySearch(dinosaurs, "Tyrannosaurus", rc);
        ShowWhere(dinosaurs, index);
    }

    private static void ShowWhere<T>(T[] array, int index)
    {
        if (index<0)
        {
            // If the index is negative, it represents the bitwise
            // complement of the next larger element in the array.
            //
            index = ~index;

            Console.Write("Not found. Sorts between: ");

            if (index == 0)
                Console.Write("beginning of array and ");
            else
                Console.Write("{0} and ", array[index-1]);

            if (index == array.Length)
                Console.WriteLine("end of array.");
            else
                Console.WriteLine("{0}.", array[index]);
        }
        else
        {
            Console.WriteLine("Found at index {0}.", index);
        }
    }
}

/* This code example produces the following output:

Pachycephalosaurus
Amargasaurus
Tyrannosaurus
Mamenchisaurus
Deinonychus
Edmontosaurus

Sort

Tyrannosaurus
Pachycephalosaurus
Mamenchisaurus
Edmontosaurus
Deinonychus
Amargasaurus

BinarySearch for 'Coelophysis':
Not found. Sorts between: Deinonychus and Amargasaurus.

BinarySearch for 'Tyrannosaurus':
Found at index 0.
 */
Imports System
Imports System.Collections.Generic

Public Class ReverseComparer
    Implements IComparer(Of String)

    Public Function Compare(ByVal x As String, _
        ByVal y As String) As Integer _
        Implements IComparer(Of String).Compare

        ' Compare y and x in reverse order.
        Return y.CompareTo(x)

    End Function
End Class

Public Class Example

    Public Shared Sub Main()

        Dim dinosaurs() As String = { _
            "Pachycephalosaurus", _
            "Amargasaurus", _
            "Tyrannosaurus", _
            "Mamenchisaurus", _
            "Deinonychus", _
            "Edmontosaurus"  }

        Console.WriteLine()
        For Each dinosaur As String In dinosaurs
            Console.WriteLine(dinosaur)
        Next

        Dim rc As New ReverseComparer()

        Console.WriteLine(vbLf & "Sort")
        Array.Sort(dinosaurs, rc)

        Console.WriteLine()
        For Each dinosaur As String In dinosaurs
            Console.WriteLine(dinosaur)
        Next

        Console.WriteLine(vbLf & _
            "BinarySearch for 'Coelophysis':")
        Dim index As Integer = _
            Array.BinarySearch(dinosaurs, "Coelophysis", rc)
        ShowWhere(dinosaurs, index)

        Console.WriteLine(vbLf & _
            "BinarySearch for 'Tyrannosaurus':")
        index = Array.BinarySearch(dinosaurs, "Tyrannosaurus", rc)
        ShowWhere(dinosaurs, index)

    End Sub

    Private Shared Sub ShowWhere(Of T) _
        (ByVal array() As T, ByVal index As Integer) 

        If index < 0 Then
            ' If the index is negative, it represents the bitwise
            ' complement of the next larger element in the array.
            '
            index = index Xor -1

            Console.Write("Not found. Sorts between: ")

            If index = 0 Then
                Console.Write("beginning of array and ")
            Else
                Console.Write("{0} and ", array(index - 1))
            End If 

            If index = array.Length Then
                Console.WriteLine("end of array.")
            Else
                Console.WriteLine("{0}.", array(index))
            End If 
        Else
            Console.WriteLine("Found at index {0}.", index)
        End If

    End Sub

End Class

' This code example produces the following output:
'
'Pachycephalosaurus
'Amargasaurus
'Tyrannosaurus
'Mamenchisaurus
'Deinonychus
'Edmontosaurus
'
'Sort
'
'Tyrannosaurus
'Pachycephalosaurus
'Mamenchisaurus
'Edmontosaurus
'Deinonychus
'Amargasaurus
'
'BinarySearch for 'Coelophysis':
'Not found. Sorts between: Deinonychus and Amargasaurus.
'
'BinarySearch for 'Tyrannosaurus':
'Found at index 0.

Remarks

If comparer is null, each element of array must implement the IComparable<T> generic interface to be capable of comparisons with every other element in array.

If the sort is not successfully completed, the results are undefined.

This method uses the introspective sort (introsort) algorithm as follows:

  • If the partition size is fewer than 16 elements, it uses an insertion sort algorithm.

  • If the number of partitions exceeds 2 * LogN, where N is the range of the input array, it uses a Heapsort algorithm.

  • Otherwise, it uses a Quicksort algorithm.

This implementation performs an unstable sort; that is, if two elements are equal, their order might not be preserved. In contrast, a stable sort preserves the order of elements that are equal.

For arrays that are sorted by using the Heapsort and Quicksort algorithms, in the worst case, this method is an O(n log n) operation, where n is the Length of array.

Notes to Callers

The .NET Framework 4 and earlier versions used only the Quicksort algorithm. Quicksort identifies invalid comparers in some situations in which the sorting operation throws an IndexOutOfRangeException exception, and throws an ArgumentException exception to the caller. Starting with the .NET Framework 4.5, it is possible that sorting operations that previously threw ArgumentException will not throw an exception, because the insertion sort and heapsort algorithms do not detect an invalid comparer. For the most part, this applies to arrays with fewer than 16 elements.

See also

Sort<T>(T[], Comparison<T>) Sort<T>(T[], Comparison<T>) Sort<T>(T[], Comparison<T>) Sort<T>(T[], Comparison<T>)

Sorts the elements in an Array using the specified Comparison<T>.

public:
generic <typename T>
 static void Sort(cli::array <T> ^ array, Comparison<T> ^ comparison);
public static void Sort<T> (T[] array, Comparison<T> comparison);
static member Sort : 'T[] * Comparison<'T> -> unit
Public Shared Sub Sort(Of T) (array As T(), comparison As Comparison(Of T))

Type Parameters

T

The type of the elements of the array.

Parameters

array
T[]

The one-dimensional, zero-based Array to sort

comparison
Comparison<T> Comparison<T> Comparison<T> Comparison<T>

The Comparison<T> to use when comparing elements.

Exceptions

The implementation of comparison caused an error during the sort. For example, comparison might not return 0 when comparing an item with itself.

Examples

The following code example demonstrates the Sort(Comparison<T>) method overload.

The code example defines an alternative comparison method for strings, named CompareDinosByLength. This method works as follows: First, the comparandsare tested fornull, and a null reference is treated as less than a non-null. Second, the string lengths are compared, and the longer string is deemed to be greater. Third, if the lengths are equal, ordinary string comparison is used.

A array of strings is created and populated with four strings, in no particular order. The list also includes an empty string and a null reference. The list is displayed, sorted using a Comparison<T> generic delegate representing the CompareDinosByLength method, and displayed again.

using namespace System;
using namespace System::Collections::Generic;

int CompareDinosByLength(String^ x, String^ y)
{
    if (x == nullptr)
    {
        if (y == nullptr)
        {
            // If x is null and y is null, they're
            // equal. 
            return 0;
        }
        else
        {
            // If x is null and y is not null, y
            // is greater. 
            return -1;
        }
    }
    else
    {
        // If x is not null...
        //
        if (y == nullptr)
            // ...and y is null, x is greater.
        {
            return 1;
        }
        else
        {
            // ...and y is not null, compare the 
            // lengths of the two strings.
            //
            int retval = x->Length.CompareTo(y->Length);

            if (retval != 0)
            {
                // If the strings are not of equal length,
                // the longer string is greater.
                //
                return retval;
            }
            else
            {
                // If the strings are of equal length,
                // sort them with ordinary string comparison.
                //
                return x->CompareTo(y);
            }
        }
    }
};

void Display(array<String^>^ arr)
{
    Console::WriteLine();
    for each(String^ s in arr)
    {
        if (s == nullptr)
            Console::WriteLine("(null)");
        else
            Console::WriteLine("\"{0}\"", s);
    }
};

void main()
{
    array<String^>^ dinosaurs = { 
        "Pachycephalosaurus",
        "Amargasaurus",
        "",
        nullptr,
        "Mamenchisaurus",
        "Deinonychus" };
    Display(dinosaurs);

    Console::WriteLine("\nSort with generic Comparison<String^> delegate:");
    Array::Sort(dinosaurs,
        gcnew Comparison<String^>(CompareDinosByLength));
    Display(dinosaurs);

}

/* This code example produces the following output:

"Pachycephalosaurus"
"Amargasaurus"
""
(null)
"Mamenchisaurus"
"Deinonychus"

Sort with generic Comparison<String^> delegate:

(null)
""
"Deinonychus"
"Amargasaurus"
"Mamenchisaurus"
"Pachycephalosaurus"
 */
using System;
using System.Collections.Generic;

public class Example
{
    private static int CompareDinosByLength(string x, string y)
    {
        if (x == null)
        {
            if (y == null)
            {
                // If x is null and y is null, they're
                // equal. 
                return 0;
            }
            else
            {
                // If x is null and y is not null, y
                // is greater. 
                return -1;
            }
        }
        else
        {
            // If x is not null...
            //
            if (y == null)
                // ...and y is null, x is greater.
            {
                return 1;
            }
            else
            {
                // ...and y is not null, compare the 
                // lengths of the two strings.
                //
                int retval = x.Length.CompareTo(y.Length);

                if (retval != 0)
                {
                    // If the strings are not of equal length,
                    // the longer string is greater.
                    //
                    return retval;
                }
                else
                {
                    // If the strings are of equal length,
                    // sort them with ordinary string comparison.
                    //
                    return x.CompareTo(y);
                }
            }
        }
    }

    public static void Main()
    {
        string[] dinosaurs = {
            "Pachycephalosaurus",
            "Amargasaurus",
            "",
            null,
            "Mamenchisaurus",
            "Deinonychus" };
        Display(dinosaurs);

        Console.WriteLine("\nSort with generic Comparison<string> delegate:");
        Array.Sort(dinosaurs, CompareDinosByLength);
        Display(dinosaurs);

    }

    private static void Display(string[] arr)
    {
        Console.WriteLine();
        foreach( string s in arr )
        {
            if (s == null)
                Console.WriteLine("(null)");
            else
                Console.WriteLine("\"{0}\"", s);
        }
    }
}

/* This code example produces the following output:

"Pachycephalosaurus"
"Amargasaurus"
""
(null)
"Mamenchisaurus"
"Deinonychus"

Sort with generic Comparison<string> delegate:

(null)
""
"Deinonychus"
"Amargasaurus"
"Mamenchisaurus"
"Pachycephalosaurus"
 */
Imports System
Imports System.Collections.Generic

Public Class Example

    Private Shared Function CompareDinosByLength( _
        ByVal x As String, ByVal y As String) As Integer

        If x Is Nothing Then
            If y Is Nothing Then 
                ' If x is Nothing and y is Nothing, they're
                ' equal. 
                Return 0
            Else
                ' If x is Nothing and y is not Nothing, y
                ' is greater. 
                Return -1
            End If
        Else
            ' If x is not Nothing...
            '
            If y Is Nothing Then
                ' ...and y is Nothing, x is greater.
                Return 1
            Else
                ' ...and y is not Nothing, compare the 
                ' lengths of the two strings.
                '
                Dim retval As Integer = _
                    x.Length.CompareTo(y.Length)

                If retval <> 0 Then 
                    ' If the strings are not of equal length,
                    ' the longer string is greater.
                    '
                    Return retval
                Else
                    ' If the strings are of equal length,
                    ' sort them with ordinary string comparison.
                    '
                    Return x.CompareTo(y)
                End If
            End If
        End If

    End Function

    Public Shared Sub Main()

        Dim dinosaurs() As String = { _
            "Pachycephalosaurus", _
            "Amargasaurus", _
            "", _
            Nothing, _
            "Mamenchisaurus", _
            "Deinonychus" }
        Display(dinosaurs)

        Console.WriteLine(vbLf & "Sort with generic Comparison(Of String) delegate:")
        Array.Sort(dinosaurs, AddressOf CompareDinosByLength)
        Display(dinosaurs)

    End Sub

    Private Shared Sub Display(ByVal arr() As String)
        Console.WriteLine()
        For Each s As String In arr
            If s Is Nothing Then
                Console.WriteLine("(Nothing)")
            Else
                Console.WriteLine("""{0}""", s)
            End If
        Next
    End Sub
End Class

' This code example produces the following output:
'
'"Pachycephalosaurus"
'"Amargasaurus"
'""
'(Nothing)
'"Mamenchisaurus"
'"Deinonychus"
'
'Sort with generic Comparison(Of String) delegate:
'
'(Nothing)
'""
'"Deinonychus"
'"Amargasaurus"
'"Mamenchisaurus"
'"Pachycephalosaurus"

Remarks

If the sort is not successfully completed, the results are undefined.

This method uses introspective sort (introsort) algorithm as follows:

  • If the partition size is fewer than 16 elements, it uses an insertion sort algorithm.

  • If the number of partitions exceeds 2 * LogN, where N is the range of the input array, it uses a Heapsort algorithm.

  • Otherwise, it uses a Quicksort algorithm.

This implementation performs an unstable sort; that is, if two elements are equal, their order might not be preserved. In contrast, a stable sort preserves the order of elements that are equal.

For arrays that are sorted by using the Heapsort and Quicksort algorithms, in the worst case, this method is an O(n log n) operation, where n is the Length of array.

Notes to Callers

The .NET Framework 4 and earlier versions used only the Quicksort algorithm. Quicksort identifies invalid comparers in some situations in which the sorting operation throws an IndexOutOfRangeException exception, and throws an ArgumentException exception to the caller. Starting with the .NET Framework 4.5, it is possible that sorting operations that previously threw ArgumentException will not throw an exception, because the insertion sort and heapsort algorithms do not detect an invalid comparer. For the most part, this applies to arrays with fewer than 16 elements.

See also

Sort<T>(T[], Int32, Int32) Sort<T>(T[], Int32, Int32) Sort<T>(T[], Int32, Int32) Sort<T>(T[], Int32, Int32)

Sorts the elements in a range of elements in an Array using the IComparable<T> generic interface implementation of each element of the Array.

public:
generic <typename T>
 static void Sort(cli::array <T> ^ array, int index, int length);
public static void Sort<T> (T[] array, int index, int length);
static member Sort : 'T[] * int * int -> unit
Public Shared Sub Sort(Of T) (array As T(), index As Integer, length As Integer)

Type Parameters

T

The type of the elements of the array.

Parameters

array
T[]

The one-dimensional, zero-based Array to sort

index
Int32 Int32 Int32 Int32

The starting index of the range to sort.

length
Int32 Int32 Int32 Int32

The number of elements in the range to sort.

Exceptions

index is less than the lower bound of array.

-or-

length is less than zero.

index and length do not specify a valid range in array.

One or more elements in array do not implement the IComparable<T> generic interface.

Examples

The following code example demonstrates the Sort<T>(T[], Int32, Int32) generic method overload and the Sort<TKey,TValue>(TKey[], TValue[], Int32, Int32, IComparer<TKey>) generic method overload for sorting a range in an array.

The code example defines an alternative comparer for strings, named ReverseCompare, which implements the IComparer<string> (IComparer(Of String) in Visual Basic, IComparer<String^> in Visual C++) generic interface. The comparer calls the CompareTo(String) method, reversing the order of the comparands so that the strings sort high-to-low instead of low-to-high.

The code example creates and displays an array of dinosaur names, consisting of three herbivores followed by three carnivores (tyrannosaurids, to be precise). The Sort<T>(T[], Int32, Int32) generic method overload is used to sort the last three elements of the array, which is then displayed. The Sort<TKey,TValue>(TKey[], TValue[], Int32, Int32, IComparer<TKey>) generic method overload is used with ReverseCompare to sort the last three elements in reverse order. The thoroughly confused dinosaurs are displayed again.

Note

The calls to the Sort<T>(T[], IComparer<T>) and BinarySearch<T>(T[], T, IComparer<T>) generic methods do not look any different from calls to their nongeneric counterparts, because Visual Basic, C#, and C++ infer the type of the generic type parameter from the type of the first argument. If you use the Ildasm.exe (IL Disassembler) to examine the Microsoft intermediate language (MSIL), you can see that the generic methods are being called.

using namespace System;
using namespace System::Collections::Generic;

public ref class ReverseComparer: IComparer<String^>
{
public:
    virtual int Compare(String^ x, String^ y)
    {
        // Compare y and x in reverse order.
        return y->CompareTo(x);
    }
};

void main()
{
    array<String^>^ dinosaurs = {"Pachycephalosaurus", 
                                 "Amargasaurus", 
                                 "Mamenchisaurus",
                                 "Tarbosaurus",
                                 "Tyrannosaurus", 
                                 "Albertasaurus"};

    Console::WriteLine();
    for each(String^ dinosaur in dinosaurs)
    {
        Console::WriteLine(dinosaur);
    }

    Console::WriteLine("\nSort(dinosaurs, 3, 3)");
    Array::Sort(dinosaurs, 3, 3);

    Console::WriteLine();
    for each(String^ dinosaur in dinosaurs)
    {
        Console::WriteLine(dinosaur);
    }

    ReverseComparer^ rc = gcnew ReverseComparer();

    Console::WriteLine("\nSort(dinosaurs, 3, 3, rc)");
    Array::Sort(dinosaurs, 3, 3, rc);

    Console::WriteLine();
    for each(String^ dinosaur in dinosaurs)
    {
        Console::WriteLine(dinosaur);
    }
}

/* This code example produces the following output:

Pachycephalosaurus
Amargasaurus
Mamenchisaurus
Tarbosaurus
Tyrannosaurus
Albertasaurus

Sort(dinosaurs, 3, 3)

Pachycephalosaurus
Amargasaurus
Mamenchisaurus
Albertasaurus
Tarbosaurus
Tyrannosaurus

Sort(dinosaurs, 3, 3, rc)

Pachycephalosaurus
Amargasaurus
Mamenchisaurus
Tyrannosaurus
Tarbosaurus
Albertasaurus
 */
using System;
using System.Collections.Generic;

public class ReverseComparer: IComparer<string>
{
    public int Compare(string x, string y)
    {
        // Compare y and x in reverse order.
        return y.CompareTo(x);
    }
}

public class Example
{
    public static void Main()
    {
        string[] dinosaurs = {"Pachycephalosaurus", 
                              "Amargasaurus", 
                              "Mamenchisaurus", 
                              "Tarbosaurus",
                              "Tyrannosaurus", 
                              "Albertasaurus"};

        Console.WriteLine();
        foreach( string dinosaur in dinosaurs )
        {
            Console.WriteLine(dinosaur);
        }

        Console.WriteLine("\nSort(dinosaurs, 3, 3)");
        Array.Sort(dinosaurs, 3, 3);

        Console.WriteLine();
        foreach( string dinosaur in dinosaurs )
        {
            Console.WriteLine(dinosaur);
        }

        ReverseComparer rc = new ReverseComparer();

        Console.WriteLine("\nSort(dinosaurs, 3, 3, rc)");
        Array.Sort(dinosaurs, 3, 3, rc);

        Console.WriteLine();
        foreach( string dinosaur in dinosaurs )
        {
            Console.WriteLine(dinosaur);
        }
    }
}

/* This code example produces the following output:

Pachycephalosaurus
Amargasaurus
Mamenchisaurus
Tarbosaurus
Tyrannosaurus
Albertasaurus

Sort(dinosaurs, 3, 3)

Pachycephalosaurus
Amargasaurus
Mamenchisaurus
Albertasaurus
Tarbosaurus
Tyrannosaurus

Sort(dinosaurs, 3, 3, rc)

Pachycephalosaurus
Amargasaurus
Mamenchisaurus
Tyrannosaurus
Tarbosaurus
Albertasaurus
 */
Imports System
Imports System.Collections.Generic

Public Class ReverseComparer
    Implements IComparer(Of String)

    Public Function Compare(ByVal x As String, _
        ByVal y As String) As Integer _
        Implements IComparer(Of String).Compare

        ' Compare y and x in reverse order.
        Return y.CompareTo(x)

    End Function
End Class

Public Class Example

    Public Shared Sub Main()

        Dim dinosaurs() As String = { _
            "Pachycephalosaurus", _
            "Amargasaurus", _
            "Mamenchisaurus", _
            "Tarbosaurus", _
            "Tyrannosaurus", _
            "Albertasaurus"  }

        Console.WriteLine()
        For Each dinosaur As String In dinosaurs
            Console.WriteLine(dinosaur)
        Next

        Console.WriteLine(vbLf & "Sort(dinosaurs, 3, 3)")
        Array.Sort(dinosaurs, 3, 3)

        Console.WriteLine()
        For Each dinosaur As String In dinosaurs
            Console.WriteLine(dinosaur)
        Next

        Dim rc As New ReverseComparer()

        Console.WriteLine(vbLf & "Sort(dinosaurs, 3, 3, rc)")
        Array.Sort(dinosaurs, 3, 3, rc)

        Console.WriteLine()
        For Each dinosaur As String In dinosaurs
            Console.WriteLine(dinosaur)
        Next

    End Sub

End Class

' This code example produces the following output:
'
'Pachycephalosaurus
'Amargasaurus
'Mamenchisaurus
'Tarbosaurus
'Tyrannosaurus
'Albertasaurus
'
'Sort(dinosaurs, 3, 3)
'
'Pachycephalosaurus
'Amargasaurus
'Mamenchisaurus
'Albertasaurus
'Tarbosaurus
'Tyrannosaurus
'
'Sort(dinosaurs, 3, 3, rc)
'
'Pachycephalosaurus
'Amargasaurus
'Mamenchisaurus
'Tyrannosaurus
'Tarbosaurus
'Albertasaurus

Remarks

Each element within the specified range of elements in array must implement the IComparable<T> generic interface to be capable of comparisons with every other element in array.

If the sort is not successfully completed, the results are undefined.

This method uses the introspective sort (introsort) algorithm as follows:

  • If the partition size is fewer than 16 elements, it uses an insertion sort algorithm.

  • If the number of partitions exceeds 2 * LogN, where N is the range of the input array, it uses a Heapsort algorithm.

  • Otherwise, it uses a Quicksort algorithm.

This implementation performs an unstable sort; that is, if two elements are equal, their order might not be preserved. In contrast, a stable sort preserves the order of elements that are equal.

For arrays that are sorted by using the Heapsort and Quicksort algorithms, in the worst case, this method is an O(n log n) operation, where n is length.

See also

Sort<T>(T[], Int32, Int32, IComparer<T>) Sort<T>(T[], Int32, Int32, IComparer<T>) Sort<T>(T[], Int32, Int32, IComparer<T>) Sort<T>(T[], Int32, Int32, IComparer<T>)

Sorts the elements in a range of elements in an Array using the specified IComparer<T> generic interface.

public:
generic <typename T>
 static void Sort(cli::array <T> ^ array, int index, int length, System::Collections::Generic::IComparer<T> ^ comparer);
public static void Sort<T> (T[] array, int index, int length, System.Collections.Generic.IComparer<T> comparer);
static member Sort : 'T[] * int * int * System.Collections.Generic.IComparer<'T> -> unit
Public Shared Sub Sort(Of T) (array As T(), index As Integer, length As Integer, comparer As IComparer(Of T))

Type Parameters

T

The type of the elements of the array.

Parameters

array
T[]

The one-dimensional, zero-based Array to sort.

index
Int32 Int32 Int32 Int32

The starting index of the range to sort.

length
Int32 Int32 Int32 Int32

The number of elements in the range to sort.

comparer
IComparer<T> IComparer<T> IComparer<T> IComparer<T>

The IComparer<T> generic interface implementation to use when comparing elements, or null to use the IComparable<T> generic interface implementation of each element.

Exceptions

index is less than the lower bound of array.

-or-

length is less than zero.

index and length do not specify a valid range in array.

-or-

The implementation of comparer caused an error during the sort. For example, comparer might not return 0 when comparing an item with itself.

comparer is null, and one or more elements in array do not implement the IComparable<T> generic interface.

Examples

The following code example demonstrates the Sort<T>(T[], Int32, Int32) generic method overload and the Sort<TKey,TValue>(TKey[], TValue[], Int32, Int32, IComparer<TKey>) generic method overload for sorting a range in an array.

The code example defines an alternative comparer for strings, named ReverseCompare, which implements the IComparer<string> (IComparer(Of String) in Visual Basic, IComparer<String^> in Visual C++) generic interface. The comparer calls the CompareTo(String) method, reversing the order of the comparands so that the strings sort high-to-low instead of low-to-high.

The code example creates and displays an array of dinosaur names, consisting of three herbivores followed by three carnivores (tyrannosaurids, to be precise). The Sort<T>(T[], Int32, Int32) generic method overload is used to sort the last three elements of the array, which is then displayed. The Sort<TKey,TValue>(TKey[], TValue[], Int32, Int32, IComparer<TKey>) generic method overload is used with ReverseCompare to sort the last three elements in reverse order. The thoroughly confused dinosaurs are displayed again.

Note

The calls to the Sort<T>(T[], IComparer<T>) and BinarySearch<T>(T[], T, IComparer<T>) generic methods do not look any different from calls to their nongeneric counterparts, because Visual Basic, C#, and C++ infer the type of the generic type parameter from the type of the first argument. If you use the Ildasm.exe (IL Disassembler) to examine the Microsoft intermediate language (MSIL), you can see that the generic methods are being called.

using namespace System;
using namespace System::Collections::Generic;

public ref class ReverseComparer: IComparer<String^>
{
public:
    virtual int Compare(String^ x, String^ y)
    {
        // Compare y and x in reverse order.
        return y->CompareTo(x);
    }
};

void main()
{
    array<String^>^ dinosaurs = {"Pachycephalosaurus", 
                                 "Amargasaurus", 
                                 "Mamenchisaurus",
                                 "Tarbosaurus",
                                 "Tyrannosaurus", 
                                 "Albertasaurus"};

    Console::WriteLine();
    for each(String^ dinosaur in dinosaurs)
    {
        Console::WriteLine(dinosaur);
    }

    Console::WriteLine("\nSort(dinosaurs, 3, 3)");
    Array::Sort(dinosaurs, 3, 3);

    Console::WriteLine();
    for each(String^ dinosaur in dinosaurs)
    {
        Console::WriteLine(dinosaur);
    }

    ReverseComparer^ rc = gcnew ReverseComparer();

    Console::WriteLine("\nSort(dinosaurs, 3, 3, rc)");
    Array::Sort(dinosaurs, 3, 3, rc);

    Console::WriteLine();
    for each(String^ dinosaur in dinosaurs)
    {
        Console::WriteLine(dinosaur);
    }
}

/* This code example produces the following output:

Pachycephalosaurus
Amargasaurus
Mamenchisaurus
Tarbosaurus
Tyrannosaurus
Albertasaurus

Sort(dinosaurs, 3, 3)

Pachycephalosaurus
Amargasaurus
Mamenchisaurus
Albertasaurus
Tarbosaurus
Tyrannosaurus

Sort(dinosaurs, 3, 3, rc)

Pachycephalosaurus
Amargasaurus
Mamenchisaurus
Tyrannosaurus
Tarbosaurus
Albertasaurus
 */
using System;
using System.Collections.Generic;

public class ReverseComparer: IComparer<string>
{
    public int Compare(string x, string y)
    {
        // Compare y and x in reverse order.
        return y.CompareTo(x);
    }
}

public class Example
{
    public static void Main()
    {
        string[] dinosaurs = {"Pachycephalosaurus", 
                              "Amargasaurus", 
                              "Mamenchisaurus", 
                              "Tarbosaurus",
                              "Tyrannosaurus", 
                              "Albertasaurus"};

        Console.WriteLine();
        foreach( string dinosaur in dinosaurs )
        {
            Console.WriteLine(dinosaur);
        }

        Console.WriteLine("\nSort(dinosaurs, 3, 3)");
        Array.Sort(dinosaurs, 3, 3);

        Console.WriteLine();
        foreach( string dinosaur in dinosaurs )
        {
            Console.WriteLine(dinosaur);
        }

        ReverseComparer rc = new ReverseComparer();

        Console.WriteLine("\nSort(dinosaurs, 3, 3, rc)");
        Array.Sort(dinosaurs, 3, 3, rc);

        Console.WriteLine();
        foreach( string dinosaur in dinosaurs )
        {
            Console.WriteLine(dinosaur);
        }
    }
}

/* This code example produces the following output:

Pachycephalosaurus
Amargasaurus
Mamenchisaurus
Tarbosaurus
Tyrannosaurus
Albertasaurus

Sort(dinosaurs, 3, 3)

Pachycephalosaurus
Amargasaurus
Mamenchisaurus
Albertasaurus
Tarbosaurus
Tyrannosaurus

Sort(dinosaurs, 3, 3, rc)

Pachycephalosaurus
Amargasaurus
Mamenchisaurus
Tyrannosaurus
Tarbosaurus
Albertasaurus
 */
Imports System
Imports System.Collections.Generic

Public Class ReverseComparer
    Implements IComparer(Of String)

    Public Function Compare(ByVal x As String, _
        ByVal y As String) As Integer _
        Implements IComparer(Of String).Compare

        ' Compare y and x in reverse order.
        Return y.CompareTo(x)

    End Function
End Class

Public Class Example

    Public Shared Sub Main()

        Dim dinosaurs() As String = { _
            "Pachycephalosaurus", _
            "Amargasaurus", _
            "Mamenchisaurus", _
            "Tarbosaurus", _
            "Tyrannosaurus", _
            "Albertasaurus"  }

        Console.WriteLine()
        For Each dinosaur As String In dinosaurs
            Console.WriteLine(dinosaur)
        Next

        Console.WriteLine(vbLf & "Sort(dinosaurs, 3, 3)")
        Array.Sort(dinosaurs, 3, 3)

        Console.WriteLine()
        For Each dinosaur As String In dinosaurs
            Console.WriteLine(dinosaur)
        Next

        Dim rc As New ReverseComparer()

        Console.WriteLine(vbLf & "Sort(dinosaurs, 3, 3, rc)")
        Array.Sort(dinosaurs, 3, 3, rc)

        Console.WriteLine()
        For Each dinosaur As String In dinosaurs
            Console.WriteLine(dinosaur)
        Next

    End Sub

End Class

' This code example produces the following output:
'
'Pachycephalosaurus
'Amargasaurus
'Mamenchisaurus
'Tarbosaurus
'Tyrannosaurus
'Albertasaurus
'
'Sort(dinosaurs, 3, 3)
'
'Pachycephalosaurus
'Amargasaurus
'Mamenchisaurus
'Albertasaurus
'Tarbosaurus
'Tyrannosaurus
'
'Sort(dinosaurs, 3, 3, rc)
'
'Pachycephalosaurus
'Amargasaurus
'Mamenchisaurus
'Tyrannosaurus
'Tarbosaurus
'Albertasaurus

Remarks

If comparer is null, each element within the specified range of elements in array must implement the IComparable<T> generic interface to be capable of comparisons with every other element in array.

If the sort is not successfully completed, the results are undefined.

This method uses the introspective sort (introsort) algorithm as follows:

  • If the partition size is fewer than 16 elements, it uses an insertion sort algorithm.

  • If the number of partitions exceeds 2 * LogN, where N is the range of the input array, it uses a Heapsort algorithm.

  • Otherwise, it uses a Quicksort algorithm.

This implementation performs an unstable sort; that is, if two elements are equal, their order might not be preserved. In contrast, a stable sort preserves the order of elements that are equal.

For arrays that are sorted by using the Heapsort and Quicksort algorithms, in the worst case, this method is an O(n log n) operation, where n is length.

Notes to Callers

The .NET Framework 4 and earlier versions used only the Quicksort algorithm. Quicksort identifies invalid comparers in some situations in which the sorting operation throws an IndexOutOfRangeException exception, and throws an ArgumentException exception to the caller. Starting with the .NET Framework 4.5, it is possible that sorting operations that previously threw ArgumentException will not throw an exception, because the insertion sort and heapsort algorithms do not detect an invalid comparer. For the most part, this applies to arrays with fewer than 16 elements.

See also

Sort<TKey,TValue>(TKey[], TValue[]) Sort<TKey,TValue>(TKey[], TValue[]) Sort<TKey,TValue>(TKey[], TValue[]) Sort<TKey,TValue>(TKey[], TValue[])

Sorts a pair of Array objects (one contains the keys and the other contains the corresponding items) based on the keys in the first Array using the IComparable<T> generic interface implementation of each key.

public:
generic <typename TKey, typename TValue>
 static void Sort(cli::array <TKey> ^ keys, cli::array <TValue> ^ items);
public static void Sort<TKey,TValue> (TKey[] keys, TValue[] items);
static member Sort : 'Key[] * 'Value[] -> unit
Public Shared Sub Sort(Of TKey, TValue) (keys As TKey(), items As TValue())

Type Parameters

TKey

The type of the elements of the key array.

TValue

The type of the elements of the items array.

Parameters

keys
TKey[]

The one-dimensional, zero-based Array that contains the keys to sort.

items
TValue[]

The one-dimensional, zero-based Array that contains the items that correspond to the keys in keys, or null to sort only keys.

Exceptions

items is not null, and the lower bound of keys does not match the lower bound of items.

-or-

items is not null, and the length of keys is greater than the length of items.

Examples

The following code example demonstrates the Sort<TKey,TValue>(TKey[], TValue[]), Sort<TKey,TValue>(TKey[], TValue[], IComparer<TKey>), Sort<TKey,TValue>(TKey[], TValue[], Int32, Int32), and Sort<TKey,TValue>(TKey[], TValue[], Int32, Int32, IComparer<TKey>) generic method overloads, for sorting pairs of arrays that represent keys and values.

The code example defines an alternative comparer for strings, named ReverseCompare, which implements the IComparer<string> (IComparer(Of String) in Visual Basic, IComparer<String^> in Visual C++) generic interface. The comparer calls the CompareTo(String) method, reversing the order of the comparands so that the strings sort high-to-low instead of low-to-high.

The code example creates and displays an array of dinosaur names (the keys) and an array of integers representing the maximum length of each dinosaur in meters (the values). The arrays are then sorted and displayed several times:

Note

The calls to the generic methods do not look any different from calls to their nongeneric counterparts, because Visual Basic, C#, and C++ infer the type of the generic type parameter from the type of the first two arguments. If you use the Ildasm.exe (IL Disassembler) to examine the Microsoft intermediate language (MSIL), you can see that the generic methods are being called.

using namespace System;
using namespace System::Collections::Generic;

public ref class ReverseComparer: IComparer<String^>
{
public:
    virtual int Compare(String^ x, String^ y)
    {
        // Compare y and x in reverse order.
        return y->CompareTo(x);
    }
};

void main()
{
    array<String^>^ dinosaurs = {
            "Seismosaurus", 
            "Chasmosaurus", 
            "Coelophysis", 
            "Mamenchisaurus", 
            "Caudipteryx", 
            "Cetiosaurus"  };

    array<int>^ dinosaurSizes = { 40, 5, 3, 22, 1, 18 };

    Console::WriteLine();
    for (int i = 0; i < dinosaurs->Length; i++)
    {
        Console::WriteLine("{0}: up to {1} meters long.", 
            dinosaurs[i], dinosaurSizes[i]);
    }

    Console::WriteLine("\nSort(dinosaurs, dinosaurSizes)");
    Array::Sort(dinosaurs, dinosaurSizes);

    Console::WriteLine();
    for (int i = 0; i < dinosaurs->Length; i++)
    {
        Console::WriteLine("{0}: up to {1} meters long.", 
            dinosaurs[i], dinosaurSizes[i]);
    }

    ReverseComparer^ rc = gcnew ReverseComparer();

    Console::WriteLine("\nSort(dinosaurs, dinosaurSizes, rc)");
    Array::Sort(dinosaurs, dinosaurSizes, rc);

    Console::WriteLine();
    for (int i = 0; i < dinosaurs->Length; i++)
    {
        Console::WriteLine("{0}: up to {1} meters long.", 
            dinosaurs[i], dinosaurSizes[i]);
    }

    Console::WriteLine("\nSort(dinosaurs, dinosaurSizes, 3, 3)");
    Array::Sort(dinosaurs, dinosaurSizes, 3, 3);

    Console::WriteLine();
    for (int i = 0; i < dinosaurs->Length; i++)
    {
        Console::WriteLine("{0}: up to {1} meters long.", 
            dinosaurs[i], dinosaurSizes[i]);
    }

    Console::WriteLine("\nSort(dinosaurs, dinosaurSizes, 3, 3, rc)");
    Array::Sort(dinosaurs, dinosaurSizes, 3, 3, rc);

    Console::WriteLine();
    for (int i = 0; i < dinosaurs->Length; i++)
    {
        Console::WriteLine("{0}: up to {1} meters long.", 
            dinosaurs[i], dinosaurSizes[i]);
    }
}

/* This code example produces the following output:

Seismosaurus: up to 40 meters long.
Chasmosaurus: up to 5 meters long.
Coelophysis: up to 3 meters long.
Mamenchisaurus: up to 22 meters long.
Caudipteryx: up to 1 meters long.
Cetiosaurus: up to 18 meters long.

Sort(dinosaurs, dinosaurSizes)

Caudipteryx: up to 1 meters long.
Cetiosaurus: up to 18 meters long.
Chasmosaurus: up to 5 meters long.
Coelophysis: up to 3 meters long.
Mamenchisaurus: up to 22 meters long.
Seismosaurus: up to 40 meters long.

Sort(dinosaurs, dinosaurSizes, rc)

Seismosaurus: up to 40 meters long.
Mamenchisaurus: up to 22 meters long.
Coelophysis: up to 3 meters long.
Chasmosaurus: up to 5 meters long.
Cetiosaurus: up to 18 meters long.
Caudipteryx: up to 1 meters long.

Sort(dinosaurs, dinosaurSizes, 3, 3)

Seismosaurus: up to 40 meters long.
Mamenchisaurus: up to 22 meters long.
Coelophysis: up to 3 meters long.
Caudipteryx: up to 1 meters long.
Cetiosaurus: up to 18 meters long.
Chasmosaurus: up to 5 meters long.

Sort(dinosaurs, dinosaurSizes, 3, 3, rc)

Seismosaurus: up to 40 meters long.
Mamenchisaurus: up to 22 meters long.
Coelophysis: up to 3 meters long.
Chasmosaurus: up to 5 meters long.
Cetiosaurus: up to 18 meters long.
Caudipteryx: up to 1 meters long.
 */
using System;
using System.Collections.Generic;

public class ReverseComparer: IComparer<string>
{
    public int Compare(string x, string y)
    {
        // Compare y and x in reverse order.
        return y.CompareTo(x);
    }
}

public class Example
{
    public static void Main()
    {
        string[] dinosaurs = {
            "Seismosaurus", 
            "Chasmosaurus", 
            "Coelophysis", 
            "Mamenchisaurus", 
            "Caudipteryx", 
            "Cetiosaurus"  };

        int[] dinosaurSizes = { 40, 5, 3, 22, 1, 18 };

        Console.WriteLine();
        for (int i = 0; i < dinosaurs.Length; i++)
        {
            Console.WriteLine("{0}: up to {1} meters long.", 
                dinosaurs[i], dinosaurSizes[i]);
        }

        Console.WriteLine("\nSort(dinosaurs, dinosaurSizes)");
        Array.Sort(dinosaurs, dinosaurSizes);

        Console.WriteLine();
        for (int i = 0; i < dinosaurs.Length; i++)
        {
            Console.WriteLine("{0}: up to {1} meters long.", 
                dinosaurs[i], dinosaurSizes[i]);
        }

        ReverseComparer rc = new ReverseComparer();

        Console.WriteLine("\nSort(dinosaurs, dinosaurSizes, rc)");
        Array.Sort(dinosaurs, dinosaurSizes, rc);

        Console.WriteLine();
        for (int i = 0; i < dinosaurs.Length; i++)
        {
            Console.WriteLine("{0}: up to {1} meters long.", 
                dinosaurs[i], dinosaurSizes[i]);
        }

        Console.WriteLine("\nSort(dinosaurs, dinosaurSizes, 3, 3)");
        Array.Sort(dinosaurs, dinosaurSizes, 3, 3);

        Console.WriteLine();
        for (int i = 0; i < dinosaurs.Length; i++)
        {
            Console.WriteLine("{0}: up to {1} meters long.", 
                dinosaurs[i], dinosaurSizes[i]);
        }

        Console.WriteLine("\nSort(dinosaurs, dinosaurSizes, 3, 3, rc)");
        Array.Sort(dinosaurs, dinosaurSizes, 3, 3, rc);

        Console.WriteLine();
        for (int i = 0; i < dinosaurs.Length; i++)
        {
            Console.WriteLine("{0}: up to {1} meters long.", 
                dinosaurs[i], dinosaurSizes[i]);
        }
    }
}

/* This code example produces the following output:

Seismosaurus: up to 40 meters long.
Chasmosaurus: up to 5 meters long.
Coelophysis: up to 3 meters long.
Mamenchisaurus: up to 22 meters long.
Caudipteryx: up to 1 meters long.
Cetiosaurus: up to 18 meters long.

Sort(dinosaurs, dinosaurSizes)

Caudipteryx: up to 1 meters long.
Cetiosaurus: up to 18 meters long.
Chasmosaurus: up to 5 meters long.
Coelophysis: up to 3 meters long.
Mamenchisaurus: up to 22 meters long.
Seismosaurus: up to 40 meters long.

Sort(dinosaurs, dinosaurSizes, rc)

Seismosaurus: up to 40 meters long.
Mamenchisaurus: up to 22 meters long.
Coelophysis: up to 3 meters long.
Chasmosaurus: up to 5 meters long.
Cetiosaurus: up to 18 meters long.
Caudipteryx: up to 1 meters long.

Sort(dinosaurs, dinosaurSizes, 3, 3)

Seismosaurus: up to 40 meters long.
Mamenchisaurus: up to 22 meters long.
Coelophysis: up to 3 meters long.
Caudipteryx: up to 1 meters long.
Cetiosaurus: up to 18 meters long.
Chasmosaurus: up to 5 meters long.

Sort(dinosaurs, dinosaurSizes, 3, 3, rc)

Seismosaurus: up to 40 meters long.
Mamenchisaurus: up to 22 meters long.
Coelophysis: up to 3 meters long.
Chasmosaurus: up to 5 meters long.
Cetiosaurus: up to 18 meters long.
Caudipteryx: up to 1 meters long.
 */
Imports System
Imports System.Collections.Generic

Public Class ReverseComparer
    Implements IComparer(Of String)

    Public Function Compare(ByVal x As String, _
        ByVal y As String) As Integer _
        Implements IComparer(Of String).Compare

        ' Compare y and x in reverse order.
        Return y.CompareTo(x)

    End Function
End Class

Public Class Example

    Public Shared Sub Main()

        Dim dinosaurs() As String = { _
            "Seismosaurus", _
            "Chasmosaurus", _
            "Coelophysis", _
            "Mamenchisaurus", _
            "Caudipteryx", _
            "Cetiosaurus"  }

        Dim dinosaurSizes() As Integer = { 40, 5, 3, 22, 1, 18 }

        Console.WriteLine()
        For i As Integer = 0 To dinosaurs.Length - 1
            Console.WriteLine("{0}: up to {1} meters long.", _
                dinosaurs(i), dinosaurSizes(i))
        Next

        Console.WriteLine(vbLf & _
            "Sort(dinosaurs, dinosaurSizes)")
        Array.Sort(dinosaurs, dinosaurSizes)

        Console.WriteLine()
        For i As Integer = 0 To dinosaurs.Length - 1
            Console.WriteLine("{0}: up to {1} meters long.", _
                dinosaurs(i), dinosaurSizes(i))
        Next

        Dim rc As New ReverseComparer()

        Console.WriteLine(vbLf & _
            "Sort(dinosaurs, dinosaurSizes, rc)")
        Array.Sort(dinosaurs, dinosaurSizes, rc)

        Console.WriteLine()
        For i As Integer = 0 To dinosaurs.Length - 1
            Console.WriteLine("{0}: up to {1} meters long.", _
                dinosaurs(i), dinosaurSizes(i))
        Next

        Console.WriteLine(vbLf & _
            "Sort(dinosaurs, dinosaurSizes, 3, 3)")
        Array.Sort(dinosaurs, dinosaurSizes, 3, 3)

        Console.WriteLine()
        For i As Integer = 0 To dinosaurs.Length - 1
            Console.WriteLine("{0}: up to {1} meters long.", _
                dinosaurs(i), dinosaurSizes(i))
        Next

        Console.WriteLine(vbLf & _
            "Sort(dinosaurs, dinosaurSizes, 3, 3, rc)")
        Array.Sort(dinosaurs, dinosaurSizes, 3, 3, rc)

        Console.WriteLine()
        For i As Integer = 0 To dinosaurs.Length - 1
            Console.WriteLine("{0}: up to {1} meters long.", _
                dinosaurs(i), dinosaurSizes(i))
        Next

    End Sub

End Class

' This code example produces the following output:
'
'Seismosaurus: up to 40 meters long.
'Chasmosaurus: up to 5 meters long.
'Coelophysis: up to 3 meters long.
'Mamenchisaurus: up to 22 meters long.
'Caudipteryx: up to 1 meters long.
'Cetiosaurus: up to 18 meters long.
'
'Sort(dinosaurs, dinosaurSizes)
'
'Caudipteryx: up to 1 meters long.
'Cetiosaurus: up to 18 meters long.
'Chasmosaurus: up to 5 meters long.
'Coelophysis: up to 3 meters long.
'Mamenchisaurus: up to 22 meters long.
'Seismosaurus: up to 40 meters long.
'
'Sort(dinosaurs, dinosaurSizes, rc)
'
'Seismosaurus: up to 40 meters long.
'Mamenchisaurus: up to 22 meters long.
'Coelophysis: up to 3 meters long.
'Chasmosaurus: up to 5 meters long.
'Cetiosaurus: up to 18 meters long.
'Caudipteryx: up to 1 meters long.
'
'Sort(dinosaurs, dinosaurSizes, 3, 3)
'
'Seismosaurus: up to 40 meters long.
'Mamenchisaurus: up to 22 meters long.
'Coelophysis: up to 3 meters long.
'Caudipteryx: up to 1 meters long.
'Cetiosaurus: up to 18 meters long.
'Chasmosaurus: up to 5 meters long.
'
'Sort(dinosaurs, dinosaurSizes, 3, 3, rc)
'
'Seismosaurus: up to 40 meters long.
'Mamenchisaurus: up to 22 meters long.
'Coelophysis: up to 3 meters long.
'Chasmosaurus: up to 5 meters long.
'Cetiosaurus: up to 18 meters long.
'Caudipteryx: up to 1 meters long.

Remarks

Each key in the keysArray has a corresponding item in the itemsArray. When a key is repositioned during the sorting, the corresponding item in the itemsArray is similarly repositioned. Therefore, the itemsArray is sorted according to the arrangement of the corresponding keys in the keysArray.

Each key in the keysArray must implement the IComparable<T> generic interface to be capable of comparisons with every other key.

You can sort if there are more items than keys, but the items that have no corresponding keys will not be sorted. You cannot sort if there are more keys than items; doing this throws an ArgumentException.

If the sort is not successfully completed, the results are undefined.

This method uses the introspective sort (introsort) algorithm as follows:

  • If the partition size is fewer than 16 elements, it uses an insertion sort algorithm.

  • If the number of partitions exceeds 2 * LogN, where N is the range of the input array, it uses a Heapsort algorithm.

  • Otherwise, it uses a Quicksort algorithm.

This implementation performs an unstable sort; that is, if two elements are equal, their order might not be preserved. In contrast, a stable sort preserves the order of elements that are equal.

For arrays that are sorted by using the Heapsort and Quicksort algorithms, in the worst case, this method is an O(n log n) operation, where n is the Length of array.

See also

Sort<TKey,TValue>(TKey[], TValue[], IComparer<TKey>) Sort<TKey,TValue>(TKey[], TValue[], IComparer<TKey>) Sort<TKey,TValue>(TKey[], TValue[], IComparer<TKey>) Sort<TKey,TValue>(TKey[], TValue[], IComparer<TKey>)

Sorts a pair of Array objects (one contains the keys and the other contains the corresponding items) based on the keys in the first Array using the specified IComparer<T> generic interface.

public:
generic <typename TKey, typename TValue>
 static void Sort(cli::array <TKey> ^ keys, cli::array <TValue> ^ items, System::Collections::Generic::IComparer<TKey> ^ comparer);
public static void Sort<TKey,TValue> (TKey[] keys, TValue[] items, System.Collections.Generic.IComparer<TKey> comparer);
static member Sort : 'Key[] * 'Value[] * System.Collections.Generic.IComparer<'Key> -> unit
Public Shared Sub Sort(Of TKey, TValue) (keys As TKey(), items As TValue(), comparer As IComparer(Of TKey))

Type Parameters

TKey

The type of the elements of the key array.

TValue

The type of the elements of the items array.

Parameters

keys
TKey[]

The one-dimensional, zero-based Array that contains the keys to sort.

items
TValue[]

The one-dimensional, zero-based Array that contains the items that correspond to the keys in keys, or null to sort only keys.

comparer
IComparer<TKey>

The IComparer<T> generic interface implementation to use when comparing elements, or null to use the IComparable<T> generic interface implementation of each element.

Exceptions

items is not null, and the lower bound of keys does not match the lower bound of items.

-or-

items is not null, and the length of keys is greater than the length of items.

-or-

The implementation of comparer caused an error during the sort. For example, comparer might not return 0 when comparing an item with itself.

comparer is null, and one or more elements in the keysArray do not implement the IComparable<T> generic interface.

Examples

The following code example demonstrates the Sort<TKey,TValue>(TKey[], TValue[]), [], TValue<xref:System.Array.Sort%60%602%28%60%600%5B%5D%2C%60%601%5B%5D%2CSystem.Collections.Generic.IComparer%7B%60%600%7D%29>,Sort<TKey,TValue>(TKey[], TValue[], Int32, Int32), and Sort<TKey,TValue>(TKey[], TValue[], Int32, Int32, IComparer<TKey>) generic method overloads, for sorting pairs of arrays that represent keys and values.

The code example defines an alternative comparer for strings, named ReverseCompare, which implements the IComparer<string> (IComparer(Of String) in Visual Basic, IComparer<String^> in Visual C++) generic interface. The comparer calls the CompareTo(String) method, reversing the order of the comparands so that the strings sort high-to-low instead of low-to-high.

The code example creates and displays an array of dinosaur names (the keys) and an array of integers representing the maximum length of each dinosaur in meters (the values). The arrays are then sorted and displayed several times:

Note

The calls to the generic methods do not look any different from calls to their nongeneric counterparts, because Visual Basic, C#, and C++ infer the type of the generic type parameter from the type of the first two arguments. If you use the Ildasm.exe (IL Disassembler) to examine the Microsoft intermediate language (MSIL), you can see that the generic methods are being called.

using namespace System;
using namespace System::Collections::Generic;

public ref class ReverseComparer: IComparer<String^>
{
public:
    virtual int Compare(String^ x, String^ y)
    {
        // Compare y and x in reverse order.
        return y->CompareTo(x);
    }
};

void main()
{
    array<String^>^ dinosaurs = {
            "Seismosaurus", 
            "Chasmosaurus", 
            "Coelophysis", 
            "Mamenchisaurus", 
            "Caudipteryx", 
            "Cetiosaurus"  };

    array<int>^ dinosaurSizes = { 40, 5, 3, 22, 1, 18 };

    Console::WriteLine();
    for (int i = 0; i < dinosaurs->Length; i++)
    {
        Console::WriteLine("{0}: up to {1} meters long.", 
            dinosaurs[i], dinosaurSizes[i]);
    }

    Console::WriteLine("\nSort(dinosaurs, dinosaurSizes)");
    Array::Sort(dinosaurs, dinosaurSizes);

    Console::WriteLine();
    for (int i = 0; i < dinosaurs->Length; i++)
    {
        Console::WriteLine("{0}: up to {1} meters long.", 
            dinosaurs[i], dinosaurSizes[i]);
    }

    ReverseComparer^ rc = gcnew ReverseComparer();

    Console::WriteLine("\nSort(dinosaurs, dinosaurSizes, rc)");
    Array::Sort(dinosaurs, dinosaurSizes, rc);

    Console::WriteLine();
    for (int i = 0; i < dinosaurs->Length; i++)
    {
        Console::WriteLine("{0}: up to {1} meters long.", 
            dinosaurs[i], dinosaurSizes[i]);
    }

    Console::WriteLine("\nSort(dinosaurs, dinosaurSizes, 3, 3)");
    Array::Sort(dinosaurs, dinosaurSizes, 3, 3);

    Console::WriteLine();
    for (int i = 0; i < dinosaurs->Length; i++)
    {
        Console::WriteLine("{0}: up to {1} meters long.", 
            dinosaurs[i], dinosaurSizes[i]);
    }

    Console::WriteLine("\nSort(dinosaurs, dinosaurSizes, 3, 3, rc)");
    Array::Sort(dinosaurs, dinosaurSizes, 3, 3, rc);

    Console::WriteLine();
    for (int i = 0; i < dinosaurs->Length; i++)
    {
        Console::WriteLine("{0}: up to {1} meters long.", 
            dinosaurs[i], dinosaurSizes[i]);
    }
}

/* This code example produces the following output:

Seismosaurus: up to 40 meters long.
Chasmosaurus: up to 5 meters long.
Coelophysis: up to 3 meters long.
Mamenchisaurus: up to 22 meters long.
Caudipteryx: up to 1 meters long.
Cetiosaurus: up to 18 meters long.

Sort(dinosaurs, dinosaurSizes)

Caudipteryx: up to 1 meters long.
Cetiosaurus: up to 18 meters long.
Chasmosaurus: up to 5 meters long.
Coelophysis: up to 3 meters long.
Mamenchisaurus: up to 22 meters long.
Seismosaurus: up to 40 meters long.

Sort(dinosaurs, dinosaurSizes, rc)

Seismosaurus: up to 40 meters long.
Mamenchisaurus: up to 22 meters long.
Coelophysis: up to 3 meters long.
Chasmosaurus: up to 5 meters long.
Cetiosaurus: up to 18 meters long.
Caudipteryx: up to 1 meters long.

Sort(dinosaurs, dinosaurSizes, 3, 3)

Seismosaurus: up to 40 meters long.
Mamenchisaurus: up to 22 meters long.
Coelophysis: up to 3 meters long.
Caudipteryx: up to 1 meters long.
Cetiosaurus: up to 18 meters long.
Chasmosaurus: up to 5 meters long.

Sort(dinosaurs, dinosaurSizes, 3, 3, rc)

Seismosaurus: up to 40 meters long.
Mamenchisaurus: up to 22 meters long.
Coelophysis: up to 3 meters long.
Chasmosaurus: up to 5 meters long.
Cetiosaurus: up to 18 meters long.
Caudipteryx: up to 1 meters long.
 */
using System;
using System.Collections.Generic;

public class ReverseComparer: IComparer<string>
{
    public int Compare(string x, string y)
    {
        // Compare y and x in reverse order.
        return y.CompareTo(x);
    }
}

public class Example
{
    public static void Main()
    {
        string[] dinosaurs = {
            "Seismosaurus", 
            "Chasmosaurus", 
            "Coelophysis", 
            "Mamenchisaurus", 
            "Caudipteryx", 
            "Cetiosaurus"  };

        int[] dinosaurSizes = { 40, 5, 3, 22, 1, 18 };

        Console.WriteLine();
        for (int i = 0; i < dinosaurs.Length; i++)
        {
            Console.WriteLine("{0}: up to {1} meters long.", 
                dinosaurs[i], dinosaurSizes[i]);
        }

        Console.WriteLine("\nSort(dinosaurs, dinosaurSizes)");
        Array.Sort(dinosaurs, dinosaurSizes);

        Console.WriteLine();
        for (int i = 0; i < dinosaurs.Length; i++)
        {
            Console.WriteLine("{0}: up to {1} meters long.", 
                dinosaurs[i], dinosaurSizes[i]);
        }

        ReverseComparer rc = new ReverseComparer();

        Console.WriteLine("\nSort(dinosaurs, dinosaurSizes, rc)");
        Array.Sort(dinosaurs, dinosaurSizes, rc);

        Console.WriteLine();
        for (int i = 0; i < dinosaurs.Length; i++)
        {
            Console.WriteLine("{0}: up to {1} meters long.", 
                dinosaurs[i], dinosaurSizes[i]);
        }

        Console.WriteLine("\nSort(dinosaurs, dinosaurSizes, 3, 3)");
        Array.Sort(dinosaurs, dinosaurSizes, 3, 3);

        Console.WriteLine();
        for (int i = 0; i < dinosaurs.Length; i++)
        {
            Console.WriteLine("{0}: up to {1} meters long.", 
                dinosaurs[i], dinosaurSizes[i]);
        }

        Console.WriteLine("\nSort(dinosaurs, dinosaurSizes, 3, 3, rc)");
        Array.Sort(dinosaurs, dinosaurSizes, 3, 3, rc);

        Console.WriteLine();
        for (int i = 0; i < dinosaurs.Length; i++)
        {
            Console.WriteLine("{0}: up to {1} meters long.", 
                dinosaurs[i], dinosaurSizes[i]);
        }
    }
}

/* This code example produces the following output:

Seismosaurus: up to 40 meters long.
Chasmosaurus: up to 5 meters long.
Coelophysis: up to 3 meters long.
Mamenchisaurus: up to 22 meters long.
Caudipteryx: up to 1 meters long.
Cetiosaurus: up to 18 meters long.

Sort(dinosaurs, dinosaurSizes)

Caudipteryx: up to 1 meters long.
Cetiosaurus: up to 18 meters long.
Chasmosaurus: up to 5 meters long.
Coelophysis: up to 3 meters long.
Mamenchisaurus: up to 22 meters long.
Seismosaurus: up to 40 meters long.

Sort(dinosaurs, dinosaurSizes, rc)

Seismosaurus: up to 40 meters long.
Mamenchisaurus: up to 22 meters long.
Coelophysis: up to 3 meters long.
Chasmosaurus: up to 5 meters long.
Cetiosaurus: up to 18 meters long.
Caudipteryx: up to 1 meters long.

Sort(dinosaurs, dinosaurSizes, 3, 3)

Seismosaurus: up to 40 meters long.
Mamenchisaurus: up to 22 meters long.
Coelophysis: up to 3 meters long.
Caudipteryx: up to 1 meters long.
Cetiosaurus: up to 18 meters long.
Chasmosaurus: up to 5 meters long.

Sort(dinosaurs, dinosaurSizes, 3, 3, rc)

Seismosaurus: up to 40 meters long.
Mamenchisaurus: up to 22 meters long.
Coelophysis: up to 3 meters long.
Chasmosaurus: up to 5 meters long.
Cetiosaurus: up to 18 meters long.
Caudipteryx: up to 1 meters long.
 */
Imports System
Imports System.Collections.Generic

Public Class ReverseComparer
    Implements IComparer(Of String)

    Public Function Compare(ByVal x As String, _
        ByVal y As String) As Integer _
        Implements IComparer(Of String).Compare

        ' Compare y and x in reverse order.
        Return y.CompareTo(x)

    End Function
End Class

Public Class Example

    Public Shared Sub Main()

        Dim dinosaurs() As String = { _
            "Seismosaurus", _
            "Chasmosaurus", _
            "Coelophysis", _
            "Mamenchisaurus", _
            "Caudipteryx", _
            "Cetiosaurus"  }

        Dim dinosaurSizes() As Integer = { 40, 5, 3, 22, 1, 18 }

        Console.WriteLine()
        For i As Integer = 0 To dinosaurs.Length - 1
            Console.WriteLine("{0}: up to {1} meters long.", _
                dinosaurs(i), dinosaurSizes(i))
        Next

        Console.WriteLine(vbLf & _
            "Sort(dinosaurs, dinosaurSizes)")
        Array.Sort(dinosaurs, dinosaurSizes)

        Console.WriteLine()
        For i As Integer = 0 To dinosaurs.Length - 1
            Console.WriteLine("{0}: up to {1} meters long.", _
                dinosaurs(i), dinosaurSizes(i))
        Next

        Dim rc As New ReverseComparer()

        Console.WriteLine(vbLf & _
            "Sort(dinosaurs, dinosaurSizes, rc)")
        Array.Sort(dinosaurs, dinosaurSizes, rc)

        Console.WriteLine()
        For i As Integer = 0 To dinosaurs.Length - 1
            Console.WriteLine("{0}: up to {1} meters long.", _
                dinosaurs(i), dinosaurSizes(i))
        Next

        Console.WriteLine(vbLf & _
            "Sort(dinosaurs, dinosaurSizes, 3, 3)")
        Array.Sort(dinosaurs, dinosaurSizes, 3, 3)

        Console.WriteLine()
        For i As Integer = 0 To dinosaurs.Length - 1
            Console.WriteLine("{0}: up to {1} meters long.", _
                dinosaurs(i), dinosaurSizes(i))
        Next

        Console.WriteLine(vbLf & _
            "Sort(dinosaurs, dinosaurSizes, 3, 3, rc)")
        Array.Sort(dinosaurs, dinosaurSizes, 3, 3, rc)

        Console.WriteLine()
        For i As Integer = 0 To dinosaurs.Length - 1
            Console.WriteLine("{0}: up to {1} meters long.", _
                dinosaurs(i), dinosaurSizes(i))
        Next

    End Sub

End Class

' This code example produces the following output:
'
'Seismosaurus: up to 40 meters long.
'Chasmosaurus: up to 5 meters long.
'Coelophysis: up to 3 meters long.
'Mamenchisaurus: up to 22 meters long.
'Caudipteryx: up to 1 meters long.
'Cetiosaurus: up to 18 meters long.
'
'Sort(dinosaurs, dinosaurSizes)
'
'Caudipteryx: up to 1 meters long.
'Cetiosaurus: up to 18 meters long.
'Chasmosaurus: up to 5 meters long.
'Coelophysis: up to 3 meters long.
'Mamenchisaurus: up to 22 meters long.
'Seismosaurus: up to 40 meters long.
'
'Sort(dinosaurs, dinosaurSizes, rc)
'
'Seismosaurus: up to 40 meters long.
'Mamenchisaurus: up to 22 meters long.
'Coelophysis: up to 3 meters long.
'Chasmosaurus: up to 5 meters long.
'Cetiosaurus: up to 18 meters long.
'Caudipteryx: up to 1 meters long.
'
'Sort(dinosaurs, dinosaurSizes, 3, 3)
'
'Seismosaurus: up to 40 meters long.
'Mamenchisaurus: up to 22 meters long.
'Coelophysis: up to 3 meters long.
'Caudipteryx: up to 1 meters long.
'Cetiosaurus: up to 18 meters long.
'Chasmosaurus: up to 5 meters long.
'
'Sort(dinosaurs, dinosaurSizes, 3, 3, rc)
'
'Seismosaurus: up to 40 meters long.
'Mamenchisaurus: up to 22 meters long.
'Coelophysis: up to 3 meters long.
'Chasmosaurus: up to 5 meters long.
'Cetiosaurus: up to 18 meters long.
'Caudipteryx: up to 1 meters long.

Remarks

Each key in the keysArray has a corresponding item in the itemsArray. When a key is repositioned during the sorting, the corresponding item in the itemsArray is similarly repositioned. Therefore, the itemsArray is sorted according to the arrangement of the corresponding keys in the keysArray.

If comparer is null, each key in the keysArray must implement the IComparable<T> generic interface to be capable of comparisons with every other key.

You can sort if there are more items than keys, but the items that have no corresponding keys will not be sorted. You cannot sort if there are more keys than items; doing this throws an ArgumentException.

If the sort is not successfully completed, the results are undefined.

This method uses the introspective sort (introsort) algorithm as follows:

  • If the partition size is fewer than 16 elements, it uses an insertion sort algorithm.

  • If the number of partitions exceeds 2 * LogN, where N is the range of the input array, it uses a Heapsort algorithm.

  • Otherwise, it uses a Quicksort algorithm.

This implementation performs an unstable sort; that is, if two elements are equal, their order might not be preserved. In contrast, a stable sort preserves the order of elements that are equal.

For arrays that are sorted by using the Heapsort and Quicksort algorithms, in the worst case, this method is an O(n log n) operation, where n is the Length of array.

Notes to Callers

The .NET Framework 4 and earlier versions used only the Quicksort algorithm. Quicksort identifies invalid comparers in some situations in which the sorting operation throws an IndexOutOfRangeException exception, and throws an ArgumentException exception to the caller. Starting with the .NET Framework 4.5, it is possible that sorting operations that previously threw ArgumentException will not throw an exception, because the insertion sort and heapsort algorithms do not detect an invalid comparer. For the most part, this applies to arrays with fewer than 16 elements.

See also

Sort<TKey,TValue>(TKey[], TValue[], Int32, Int32) Sort<TKey,TValue>(TKey[], TValue[], Int32, Int32) Sort<TKey,TValue>(TKey[], TValue[], Int32, Int32) Sort<TKey,TValue>(TKey[], TValue[], Int32, Int32)

Sorts a range of elements in a pair of Array objects (one contains the keys and the other contains the corresponding items) based on the keys in the first Array using the IComparable<T> generic interface implementation of each key.

public:
generic <typename TKey, typename TValue>
 static void Sort(cli::array <TKey> ^ keys, cli::array <TValue> ^ items, int index, int length);
public static void Sort<TKey,TValue> (TKey[] keys, TValue[] items, int index, int length);
static member Sort : 'Key[] * 'Value[] * int * int -> unit
Public Shared Sub Sort(Of TKey, TValue) (keys As TKey(), items As TValue(), index As Integer, length As Integer)

Type Parameters

TKey

The type of the elements of the key array.

TValue

The type of the elements of the items array.

Parameters

keys
TKey[]

The one-dimensional, zero-based Array that contains the keys to sort.

items
TValue[]

The one-dimensional, zero-based Array that contains the items that correspond to the keys in keys, or null to sort only keys.

index
Int32 Int32 Int32 Int32

The starting index of the range to sort.

length
Int32 Int32 Int32 Int32

The number of elements in the range to sort.

Exceptions

index is less than the lower bound of keys.

-or-

length is less than zero.

items is not null, and the lower bound of keys does not match the lower bound of items.

-or-

items is not null, and the length of keys is greater than the length of items.

-or-

index and length do not specify a valid range in the keysArray.

-or-

items is not null, and index and length do not specify a valid range in the itemsArray.

Examples

The following code example demonstrates the Sort<TKey,TValue>(TKey[], TValue[]), Sort<TKey,TValue>(TKey[], TValue[], IComparer<TKey>), [], TValue<xref:System.Array.Sort%60%602%28%60%600%5B%5D%2C%60%601%5B%5D%2CSystem.Int32%2CSystem.Int32%29>, and Sort<TKey,TValue>(TKey[], TValue[], Int32, Int32, IComparer<TKey>) generic method overloads, for sorting pairs of arrays that represent keys and values.

The code example defines an alternative comparer for strings, named ReverseCompare, which implements the IComparer<string> (IComparer(Of String) in Visual Basic, IComparer<String^> in Visual C++) generic interface. The comparer calls the CompareTo(String) method, reversing the order of the comparands so that the strings sort high-to-low instead of low-to-high.

The code example creates and displays an array of dinosaur names (the keys) and an array of integers representing the maximum length of each dinosaur in meters (the values). The arrays are then sorted and displayed several times:

Note

The calls to the generic methods do not look any different from calls to their nongeneric counterparts, because Visual Basic, C#, and C++ infer the type of the generic type parameter from the type of the first two arguments. If you use the Ildasm.exe (IL Disassembler) to examine the Microsoft intermediate language (MSIL), you can see that the generic methods are being called.

using namespace System;
using namespace System::Collections::Generic;

public ref class ReverseComparer: IComparer<String^>
{
public:
    virtual int Compare(String^ x, String^ y)
    {
        // Compare y and x in reverse order.
        return y->CompareTo(x);
    }
};

void main()
{
    array<String^>^ dinosaurs = {
            "Seismosaurus", 
            "Chasmosaurus", 
            "Coelophysis", 
            "Mamenchisaurus", 
            "Caudipteryx", 
            "Cetiosaurus"  };

    array<int>^ dinosaurSizes = { 40, 5, 3, 22, 1, 18 };

    Console::WriteLine();
    for (int i = 0; i < dinosaurs->Length; i++)
    {
        Console::WriteLine("{0}: up to {1} meters long.", 
            dinosaurs[i], dinosaurSizes[i]);
    }

    Console::WriteLine("\nSort(dinosaurs, dinosaurSizes)");
    Array::Sort(dinosaurs, dinosaurSizes);

    Console::WriteLine();
    for (int i = 0; i < dinosaurs->Length; i++)
    {
        Console::WriteLine("{0}: up to {1} meters long.", 
            dinosaurs[i], dinosaurSizes[i]);
    }

    ReverseComparer^ rc = gcnew ReverseComparer();

    Console::WriteLine("\nSort(dinosaurs, dinosaurSizes, rc)");
    Array::Sort(dinosaurs, dinosaurSizes, rc);

    Console::WriteLine();
    for (int i = 0; i < dinosaurs->Length; i++)
    {
        Console::WriteLine("{0}: up to {1} meters long.", 
            dinosaurs[i], dinosaurSizes[i]);
    }

    Console::WriteLine("\nSort(dinosaurs, dinosaurSizes, 3, 3)");
    Array::Sort(dinosaurs, dinosaurSizes, 3, 3);

    Console::WriteLine();
    for (int i = 0; i < dinosaurs->Length; i++)
    {
        Console::WriteLine("{0}: up to {1} meters long.", 
            dinosaurs[i], dinosaurSizes[i]);
    }

    Console::WriteLine("\nSort(dinosaurs, dinosaurSizes, 3, 3, rc)");
    Array::Sort(dinosaurs, dinosaurSizes, 3, 3, rc);

    Console::WriteLine();
    for (int i = 0; i < dinosaurs->Length; i++)
    {
        Console::WriteLine("{0}: up to {1} meters long.", 
            dinosaurs[i], dinosaurSizes[i]);
    }
}

/* This code example produces the following output:

Seismosaurus: up to 40 meters long.
Chasmosaurus: up to 5 meters long.
Coelophysis: up to 3 meters long.
Mamenchisaurus: up to 22 meters long.
Caudipteryx: up to 1 meters long.
Cetiosaurus: up to 18 meters long.

Sort(dinosaurs, dinosaurSizes)

Caudipteryx: up to 1 meters long.
Cetiosaurus: up to 18 meters long.
Chasmosaurus: up to 5 meters long.
Coelophysis: up to 3 meters long.
Mamenchisaurus: up to 22 meters long.
Seismosaurus: up to 40 meters long.

Sort(dinosaurs, dinosaurSizes, rc)

Seismosaurus: up to 40 meters long.
Mamenchisaurus: up to 22 meters long.
Coelophysis: up to 3 meters long.
Chasmosaurus: up to 5 meters long.
Cetiosaurus: up to 18 meters long.
Caudipteryx: up to 1 meters long.

Sort(dinosaurs, dinosaurSizes, 3, 3)

Seismosaurus: up to 40 meters long.
Mamenchisaurus: up to 22 meters long.
Coelophysis: up to 3 meters long.
Caudipteryx: up to 1 meters long.
Cetiosaurus: up to 18 meters long.
Chasmosaurus: up to 5 meters long.

Sort(dinosaurs, dinosaurSizes, 3, 3, rc)

Seismosaurus: up to 40 meters long.
Mamenchisaurus: up to 22 meters long.
Coelophysis: up to 3 meters long.
Chasmosaurus: up to 5 meters long.
Cetiosaurus: up to 18 meters long.
Caudipteryx: up to 1 meters long.
 */
using System;
using System.Collections.Generic;

public class ReverseComparer: IComparer<string>
{
    public int Compare(string x, string y)
    {
        // Compare y and x in reverse order.
        return y.CompareTo(x);
    }
}

public class Example
{
    public static void Main()
    {
        string[] dinosaurs = {
            "Seismosaurus", 
            "Chasmosaurus", 
            "Coelophysis", 
            "Mamenchisaurus", 
            "Caudipteryx", 
            "Cetiosaurus"  };

        int[] dinosaurSizes = { 40, 5, 3, 22, 1, 18 };

        Console.WriteLine();
        for (int i = 0; i < dinosaurs.Length; i++)
        {
            Console.WriteLine("{0}: up to {1} meters long.", 
                dinosaurs[i], dinosaurSizes[i]);
        }

        Console.WriteLine("\nSort(dinosaurs, dinosaurSizes)");
        Array.Sort(dinosaurs, dinosaurSizes);

        Console.WriteLine();
        for (int i = 0; i < dinosaurs.Length; i++)
        {
            Console.WriteLine("{0}: up to {1} meters long.", 
                dinosaurs[i], dinosaurSizes[i]);
        }

        ReverseComparer rc = new ReverseComparer();

        Console.WriteLine("\nSort(dinosaurs, dinosaurSizes, rc)");
        Array.Sort(dinosaurs, dinosaurSizes, rc);

        Console.WriteLine();
        for (int i = 0; i < dinosaurs.Length; i++)
        {
            Console.WriteLine("{0}: up to {1} meters long.", 
                dinosaurs[i], dinosaurSizes[i]);
        }

        Console.WriteLine("\nSort(dinosaurs, dinosaurSizes, 3, 3)");
        Array.Sort(dinosaurs, dinosaurSizes, 3, 3);

        Console.WriteLine();
        for (int i = 0; i < dinosaurs.Length; i++)
        {
            Console.WriteLine("{0}: up to {1} meters long.", 
                dinosaurs[i], dinosaurSizes[i]);
        }

        Console.WriteLine("\nSort(dinosaurs, dinosaurSizes, 3, 3, rc)");
        Array.Sort(dinosaurs, dinosaurSizes, 3, 3, rc);

        Console.WriteLine();
        for (int i = 0; i < dinosaurs.Length; i++)
        {
            Console.WriteLine("{0}: up to {1} meters long.", 
                dinosaurs[i], dinosaurSizes[i]);
        }
    }
}

/* This code example produces the following output:

Seismosaurus: up to 40 meters long.
Chasmosaurus: up to 5 meters long.
Coelophysis: up to 3 meters long.
Mamenchisaurus: up to 22 meters long.
Caudipteryx: up to 1 meters long.
Cetiosaurus: up to 18 meters long.

Sort(dinosaurs, dinosaurSizes)

Caudipteryx: up to 1 meters long.
Cetiosaurus: up to 18 meters long.
Chasmosaurus: up to 5 meters long.
Coelophysis: up to 3 meters long.
Mamenchisaurus: up to 22 meters long.
Seismosaurus: up to 40 meters long.

Sort(dinosaurs, dinosaurSizes, rc)

Seismosaurus: up to 40 meters long.
Mamenchisaurus: up to 22 meters long.
Coelophysis: up to 3 meters long.
Chasmosaurus: up to 5 meters long.
Cetiosaurus: up to 18 meters long.
Caudipteryx: up to 1 meters long.

Sort(dinosaurs, dinosaurSizes, 3, 3)

Seismosaurus: up to 40 meters long.
Mamenchisaurus: up to 22 meters long.
Coelophysis: up to 3 meters long.
Caudipteryx: up to 1 meters long.
Cetiosaurus: up to 18 meters long.
Chasmosaurus: up to 5 meters long.

Sort(dinosaurs, dinosaurSizes, 3, 3, rc)

Seismosaurus: up to 40 meters long.
Mamenchisaurus: up to 22 meters long.
Coelophysis: up to 3 meters long.
Chasmosaurus: up to 5 meters long.
Cetiosaurus: up to 18 meters long.
Caudipteryx: up to 1 meters long.
 */
Imports System
Imports System.Collections.Generic

Public Class ReverseComparer
    Implements IComparer(Of String)

    Public Function Compare(ByVal x As String, _
        ByVal y As String) As Integer _
        Implements IComparer(Of String).Compare

        ' Compare y and x in reverse order.
        Return y.CompareTo(x)

    End Function
End Class

Public Class Example

    Public Shared Sub Main()

        Dim dinosaurs() As String = { _
            "Seismosaurus", _
            "Chasmosaurus", _
            "Coelophysis", _
            "Mamenchisaurus", _
            "Caudipteryx", _
            "Cetiosaurus"  }

        Dim dinosaurSizes() As Integer = { 40, 5, 3, 22, 1, 18 }

        Console.WriteLine()
        For i As Integer = 0 To dinosaurs.Length - 1
            Console.WriteLine("{0}: up to {1} meters long.", _
                dinosaurs(i), dinosaurSizes(i))
        Next

        Console.WriteLine(vbLf & _
            "Sort(dinosaurs, dinosaurSizes)")
        Array.Sort(dinosaurs, dinosaurSizes)

        Console.WriteLine()
        For i As Integer = 0 To dinosaurs.Length - 1
            Console.WriteLine("{0}: up to {1} meters long.", _
                dinosaurs(i), dinosaurSizes(i))
        Next

        Dim rc As New ReverseComparer()

        Console.WriteLine(vbLf & _
            "Sort(dinosaurs, dinosaurSizes, rc)")
        Array.Sort(dinosaurs, dinosaurSizes, rc)

        Console.WriteLine()
        For i As Integer = 0 To dinosaurs.Length - 1
            Console.WriteLine("{0}: up to {1} meters long.", _
                dinosaurs(i), dinosaurSizes(i))
        Next

        Console.WriteLine(vbLf & _
            "Sort(dinosaurs, dinosaurSizes, 3, 3)")
        Array.Sort(dinosaurs, dinosaurSizes, 3, 3)

        Console.WriteLine()
        For i As Integer = 0 To dinosaurs.Length - 1
            Console.WriteLine("{0}: up to {1} meters long.", _
                dinosaurs(i), dinosaurSizes(i))
        Next

        Console.WriteLine(vbLf & _
            "Sort(dinosaurs, dinosaurSizes, 3, 3, rc)")
        Array.Sort(dinosaurs, dinosaurSizes, 3, 3, rc)

        Console.WriteLine()
        For i As Integer = 0 To dinosaurs.Length - 1
            Console.WriteLine("{0}: up to {1} meters long.", _
                dinosaurs(i), dinosaurSizes(i))
        Next

    End Sub

End Class

' This code example produces the following output:
'
'Seismosaurus: up to 40 meters long.
'Chasmosaurus: up to 5 meters long.
'Coelophysis: up to 3 meters long.
'Mamenchisaurus: up to 22 meters long.
'Caudipteryx: up to 1 meters long.
'Cetiosaurus: up to 18 meters long.
'
'Sort(dinosaurs, dinosaurSizes)
'
'Caudipteryx: up to 1 meters long.
'Cetiosaurus: up to 18 meters long.
'Chasmosaurus: up to 5 meters long.
'Coelophysis: up to 3 meters long.
'Mamenchisaurus: up to 22 meters long.
'Seismosaurus: up to 40 meters long.
'
'Sort(dinosaurs, dinosaurSizes, rc)
'
'Seismosaurus: up to 40 meters long.
'Mamenchisaurus: up to 22 meters long.
'Coelophysis: up to 3 meters long.
'Chasmosaurus: up to 5 meters long.
'Cetiosaurus: up to 18 meters long.
'Caudipteryx: up to 1 meters long.
'
'Sort(dinosaurs, dinosaurSizes, 3, 3)
'
'Seismosaurus: up to 40 meters long.
'Mamenchisaurus: up to 22 meters long.
'Coelophysis: up to 3 meters long.
'Caudipteryx: up to 1 meters long.
'Cetiosaurus: up to 18 meters long.
'Chasmosaurus: up to 5 meters long.
'
'Sort(dinosaurs, dinosaurSizes, 3, 3, rc)
'
'Seismosaurus: up to 40 meters long.
'Mamenchisaurus: up to 22 meters long.
'Coelophysis: up to 3 meters long.
'Chasmosaurus: up to 5 meters long.
'Cetiosaurus: up to 18 meters long.
'Caudipteryx: up to 1 meters long.

Remarks

Each key in the keysArray has a corresponding item in the itemsArray. When a key is repositioned during the sorting, the corresponding item in the itemsArray is similarly repositioned. Therefore, the itemsArray is sorted according to the arrangement of the corresponding keys in the keysArray.

Each key within the specified range of elements in the keysArray must implement the IComparable<T> generic interface to be capable of comparisons with every other key.

You can sort if there are more items than keys, but the items that have no corresponding keys will not be sorted. You cannot sort if there are more keys than items; doing this throws an ArgumentException.

If the sort is not successfully completed, the results are undefined.

This method uses the introspective sort (introsort) algorithm as follows:

  • If the partition size is fewer than 16 elements, it uses an insertion sort algorithm.

  • If the number of partitions exceeds 2 * LogN, where N is the range of the input array, it uses a Heapsort algorithm.

  • Otherwise, it uses a Quicksort algorithm.

This implementation performs an unstable sort; that is, if two elements are equal, their order might not be preserved. In contrast, a stable sort preserves the order of elements that are equal.

For arrays that are sorted by using the Heapsort and Quicksort algorithms, in the worst case, this method is an O(n log n) operation, where n is length.

See also

Sort<TKey,TValue>(TKey[], TValue[], Int32, Int32, IComparer<TKey>) Sort<TKey,TValue>(TKey[], TValue[], Int32, Int32, IComparer<TKey>) Sort<TKey,TValue>(TKey[], TValue[], Int32, Int32, IComparer<TKey>) Sort<TKey,TValue>(TKey[], TValue[], Int32, Int32, IComparer<TKey>)

Sorts a range of elements in a pair of Array objects (one contains the keys and the other contains the corresponding items) based on the keys in the first Array using the specified IComparer<T> generic interface.

public:
generic <typename TKey, typename TValue>
 static void Sort(cli::array <TKey> ^ keys, cli::array <TValue> ^ items, int index, int length, System::Collections::Generic::IComparer<TKey> ^ comparer);
public static void Sort<TKey,TValue> (TKey[] keys, TValue[] items, int index, int length, System.Collections.Generic.IComparer<TKey> comparer);
static member Sort : 'Key[] * 'Value[] * int * int * System.Collections.Generic.IComparer<'Key> -> unit
Public Shared Sub Sort(Of TKey, TValue) (keys As TKey(), items As TValue(), index As Integer, length As Integer, comparer As IComparer(Of TKey))

Type Parameters

TKey

The type of the elements of the key array.

TValue

The type of the elements of the items array.

Parameters

keys
TKey[]

The one-dimensional, zero-based Array that contains the keys to sort.

items
TValue[]

The one-dimensional, zero-based Array that contains the items that correspond to the keys in keys, or null to sort only keys.

index
Int32 Int32 Int32 Int32

The starting index of the range to sort.

length
Int32 Int32 Int32 Int32

The number of elements in the range to sort.

comparer
IComparer<TKey>

The IComparer<T> generic interface implementation to use when comparing elements, or null to use the IComparable<T> generic interface implementation of each element.

Exceptions

index is less than the lower bound of keys.

-or-

length is less than zero.

items is not null, and the lower bound of keys does not match the lower bound of items.

-or-

items is not null, and the length of keys is greater than the length of items.

-or-

index and length do not specify a valid range in the keysArray.

-or-

items is not null, and index and length do not specify a valid range in the itemsArray.

-or-

The implementation of comparer caused an error during the sort. For example, comparer might not return 0 when comparing an item with itself.

comparer is null, and one or more elements in the keysArray do not implement the IComparable<T> generic interface.

Examples

The following code example demonstrates the Sort<TKey,TValue>(TKey[], TValue[]), Sort<TKey,TValue>(TKey[], TValue[], IComparer<TKey>), Sort<TKey,TValue>(TKey[], TValue[], Int32, Int32), and [], TValue<xref:System.Array.Sort%60%602%28%60%600%5B%5D%2C%60%601%5B%5D%2CSystem.Int32%2CSystem.Int32%2CSystem.Collections.Generic.IComparer%7B%60%600%7D%29> generic method overloads, for sorting pairs of arrays that represent keys and values.

The code example defines an alternative comparer for strings, named ReverseCompare, which implements the IComparer<string>(IComparer(Of String) in Visual Basic, IComparer<String^> in Visual C++) generic interface. The comparer calls the CompareTo(String) method, reversing the order of the comparands so that the strings sort high-to-low instead of low-to-high.

The code example creates and displays an array of dinosaur names (the keys) and an array of integers representing the maximum length of each dinosaur in meters (the values). The arrays are then sorted and displayed several times:

Note

The calls to the generic methods do not look any different from calls to their nongeneric counterparts, because Visual Basic, C#, and C++ infer the type of the generic type parameter from the type of the first two arguments. If you use the Ildasm.exe (IL Disassembler) to examine the Microsoft intermediate language (MSIL), you can see that the generic methods are being called.

using namespace System;
using namespace System::Collections::Generic;

public ref class ReverseComparer: IComparer<String^>
{
public:
    virtual int Compare(String^ x, String^ y)
    {
        // Compare y and x in reverse order.
        return y->CompareTo(x);
    }
};

void main()
{
    array<String^>^ dinosaurs = {
            "Seismosaurus", 
            "Chasmosaurus", 
            "Coelophysis", 
            "Mamenchisaurus", 
            "Caudipteryx", 
            "Cetiosaurus"  };

    array<int>^ dinosaurSizes = { 40, 5, 3, 22, 1, 18 };

    Console::WriteLine();
    for (int i = 0; i < dinosaurs->Length; i++)
    {
        Console::WriteLine("{0}: up to {1} meters long.", 
            dinosaurs[i], dinosaurSizes[i]);
    }

    Console::WriteLine("\nSort(dinosaurs, dinosaurSizes)");
    Array::Sort(dinosaurs, dinosaurSizes);

    Console::WriteLine();
    for (int i = 0; i < dinosaurs->Length; i++)
    {
        Console::WriteLine("{0}: up to {1} meters long.", 
            dinosaurs[i], dinosaurSizes[i]);
    }

    ReverseComparer^ rc = gcnew ReverseComparer();

    Console::WriteLine("\nSort(dinosaurs, dinosaurSizes, rc)");
    Array::Sort(dinosaurs, dinosaurSizes, rc);

    Console::WriteLine();
    for (int i = 0; i < dinosaurs->Length; i++)
    {
        Console::WriteLine("{0}: up to {1} meters long.", 
            dinosaurs[i], dinosaurSizes[i]);
    }

    Console::WriteLine("\nSort(dinosaurs, dinosaurSizes, 3, 3)");
    Array::Sort(dinosaurs, dinosaurSizes, 3, 3);

    Console::WriteLine();
    for (int i = 0; i < dinosaurs->Length; i++)
    {
        Console::WriteLine("{0}: up to {1} meters long.", 
            dinosaurs[i], dinosaurSizes[i]);
    }

    Console::WriteLine("\nSort(dinosaurs, dinosaurSizes, 3, 3, rc)");
    Array::Sort(dinosaurs, dinosaurSizes, 3, 3, rc);

    Console::WriteLine();
    for (int i = 0; i < dinosaurs->Length; i++)
    {
        Console::WriteLine("{0}: up to {1} meters long.", 
            dinosaurs[i], dinosaurSizes[i]);
    }
}

/* This code example produces the following output:

Seismosaurus: up to 40 meters long.
Chasmosaurus: up to 5 meters long.
Coelophysis: up to 3 meters long.
Mamenchisaurus: up to 22 meters long.
Caudipteryx: up to 1 meters long.
Cetiosaurus: up to 18 meters long.

Sort(dinosaurs, dinosaurSizes)

Caudipteryx: up to 1 meters long.
Cetiosaurus: up to 18 meters long.
Chasmosaurus: up to 5 meters long.
Coelophysis: up to 3 meters long.
Mamenchisaurus: up to 22 meters long.
Seismosaurus: up to 40 meters long.

Sort(dinosaurs, dinosaurSizes, rc)

Seismosaurus: up to 40 meters long.
Mamenchisaurus: up to 22 meters long.
Coelophysis: up to 3 meters long.
Chasmosaurus: up to 5 meters long.
Cetiosaurus: up to 18 meters long.
Caudipteryx: up to 1 meters long.

Sort(dinosaurs, dinosaurSizes, 3, 3)

Seismosaurus: up to 40 meters long.
Mamenchisaurus: up to 22 meters long.
Coelophysis: up to 3 meters long.
Caudipteryx: up to 1 meters long.
Cetiosaurus: up to 18 meters long.
Chasmosaurus: up to 5 meters long.

Sort(dinosaurs, dinosaurSizes, 3, 3, rc)

Seismosaurus: up to 40 meters long.
Mamenchisaurus: up to 22 meters long.
Coelophysis: up to 3 meters long.
Chasmosaurus: up to 5 meters long.
Cetiosaurus: up to 18 meters long.
Caudipteryx: up to 1 meters long.
 */
using System;
using System.Collections.Generic;

public class ReverseComparer: IComparer<string>
{
    public int Compare(string x, string y)
    {
        // Compare y and x in reverse order.
        return y.CompareTo(x);
    }
}

public class Example
{
    public static void Main()
    {
        string[] dinosaurs = {
            "Seismosaurus", 
            "Chasmosaurus", 
            "Coelophysis", 
            "Mamenchisaurus", 
            "Caudipteryx", 
            "Cetiosaurus"  };

        int[] dinosaurSizes = { 40, 5, 3, 22, 1, 18 };

        Console.WriteLine();
        for (int i = 0; i < dinosaurs.Length; i++)
        {
            Console.WriteLine("{0}: up to {1} meters long.", 
                dinosaurs[i], dinosaurSizes[i]);
        }

        Console.WriteLine("\nSort(dinosaurs, dinosaurSizes)");
        Array.Sort(dinosaurs, dinosaurSizes);

        Console.WriteLine();
        for (int i = 0; i < dinosaurs.Length; i++)
        {
            Console.WriteLine("{0}: up to {1} meters long.", 
                dinosaurs[i], dinosaurSizes[i]);
        }

        ReverseComparer rc = new ReverseComparer();

        Console.WriteLine("\nSort(dinosaurs, dinosaurSizes, rc)");
        Array.Sort(dinosaurs, dinosaurSizes, rc);

        Console.WriteLine();
        for (int i = 0; i < dinosaurs.Length; i++)
        {
            Console.WriteLine("{0}: up to {1} meters long.", 
                dinosaurs[i], dinosaurSizes[i]);
        }

        Console.WriteLine("\nSort(dinosaurs, dinosaurSizes, 3, 3)");
        Array.Sort(dinosaurs, dinosaurSizes, 3, 3);

        Console.WriteLine();
        for (int i = 0; i < dinosaurs.Length; i++)
        {
            Console.WriteLine("{0}: up to {1} meters long.", 
                dinosaurs[i], dinosaurSizes[i]);
        }

        Console.WriteLine("\nSort(dinosaurs, dinosaurSizes, 3, 3, rc)");
        Array.Sort(dinosaurs, dinosaurSizes, 3, 3, rc);

        Console.WriteLine();
        for (int i = 0; i < dinosaurs.Length; i++)
        {
            Console.WriteLine("{0}: up to {1} meters long.", 
                dinosaurs[i], dinosaurSizes[i]);
        }
    }
}

/* This code example produces the following output:

Seismosaurus: up to 40 meters long.
Chasmosaurus: up to 5 meters long.
Coelophysis: up to 3 meters long.
Mamenchisaurus: up to 22 meters long.
Caudipteryx: up to 1 meters long.
Cetiosaurus: up to 18 meters long.

Sort(dinosaurs, dinosaurSizes)

Caudipteryx: up to 1 meters long.
Cetiosaurus: up to 18 meters long.
Chasmosaurus: up to 5 meters long.
Coelophysis: up to 3 meters long.
Mamenchisaurus: up to 22 meters long.
Seismosaurus: up to 40 meters long.

Sort(dinosaurs, dinosaurSizes, rc)

Seismosaurus: up to 40 meters long.
Mamenchisaurus: up to 22 meters long.
Coelophysis: up to 3 meters long.
Chasmosaurus: up to 5 meters long.
Cetiosaurus: up to 18 meters long.
Caudipteryx: up to 1 meters long.

Sort(dinosaurs, dinosaurSizes, 3, 3)

Seismosaurus: up to 40 meters long.
Mamenchisaurus: up to 22 meters long.
Coelophysis: up to 3 meters long.
Caudipteryx: up to 1 meters long.
Cetiosaurus: up to 18 meters long.
Chasmosaurus: up to 5 meters long.

Sort(dinosaurs, dinosaurSizes, 3, 3, rc)

Seismosaurus: up to 40 meters long.
Mamenchisaurus: up to 22 meters long.
Coelophysis: up to 3 meters long.
Chasmosaurus: up to 5 meters long.
Cetiosaurus: up to 18 meters long.
Caudipteryx: up to 1 meters long.
 */
Imports System
Imports System.Collections.Generic

Public Class ReverseComparer
    Implements IComparer(Of String)

    Public Function Compare(ByVal x As String, _
        ByVal y As String) As Integer _
        Implements IComparer(Of String).Compare

        ' Compare y and x in reverse order.
        Return y.CompareTo(x)

    End Function
End Class

Public Class Example

    Public Shared Sub Main()

        Dim dinosaurs() As String = { _
            "Seismosaurus", _
            "Chasmosaurus", _
            "Coelophysis", _
            "Mamenchisaurus", _
            "Caudipteryx", _
            "Cetiosaurus"  }

        Dim dinosaurSizes() As Integer = { 40, 5, 3, 22, 1, 18 }

        Console.WriteLine()
        For i As Integer = 0 To dinosaurs.Length - 1
            Console.WriteLine("{0}: up to {1} meters long.", _
                dinosaurs(i), dinosaurSizes(i))
        Next

        Console.WriteLine(vbLf & _
            "Sort(dinosaurs, dinosaurSizes)")
        Array.Sort(dinosaurs, dinosaurSizes)

        Console.WriteLine()
        For i As Integer = 0 To dinosaurs.Length - 1
            Console.WriteLine("{0}: up to {1} meters long.", _
                dinosaurs(i), dinosaurSizes(i))
        Next

        Dim rc As New ReverseComparer()

        Console.WriteLine(vbLf & _
            "Sort(dinosaurs, dinosaurSizes, rc)")
        Array.Sort(dinosaurs, dinosaurSizes, rc)

        Console.WriteLine()
        For i As Integer = 0 To dinosaurs.Length - 1
            Console.WriteLine("{0}: up to {1} meters long.", _
                dinosaurs(i), dinosaurSizes(i))
        Next

        Console.WriteLine(vbLf & _
            "Sort(dinosaurs, dinosaurSizes, 3, 3)")
        Array.Sort(dinosaurs, dinosaurSizes, 3, 3)

        Console.WriteLine()
        For i As Integer = 0 To dinosaurs.Length - 1
            Console.WriteLine("{0}: up to {1} meters long.", _
                dinosaurs(i), dinosaurSizes(i))
        Next

        Console.WriteLine(vbLf & _
            "Sort(dinosaurs, dinosaurSizes, 3, 3, rc)")
        Array.Sort(dinosaurs, dinosaurSizes, 3, 3, rc)

        Console.WriteLine()
        For i As Integer = 0 To dinosaurs.Length - 1
            Console.WriteLine("{0}: up to {1} meters long.", _
                dinosaurs(i), dinosaurSizes(i))
        Next

    End Sub

End Class

' This code example produces the following output:
'
'Seismosaurus: up to 40 meters long.
'Chasmosaurus: up to 5 meters long.
'Coelophysis: up to 3 meters long.
'Mamenchisaurus: up to 22 meters long.
'Caudipteryx: up to 1 meters long.
'Cetiosaurus: up to 18 meters long.
'
'Sort(dinosaurs, dinosaurSizes)
'
'Caudipteryx: up to 1 meters long.
'Cetiosaurus: up to 18 meters long.
'Chasmosaurus: up to 5 meters long.
'Coelophysis: up to 3 meters long.
'Mamenchisaurus: up to 22 meters long.
'Seismosaurus: up to 40 meters long.
'
'Sort(dinosaurs, dinosaurSizes, rc)
'
'Seismosaurus: up to 40 meters long.
'Mamenchisaurus: up to 22 meters long.
'Coelophysis: up to 3 meters long.
'Chasmosaurus: up to 5 meters long.
'Cetiosaurus: up to 18 meters long.
'Caudipteryx: up to 1 meters long.
'
'Sort(dinosaurs, dinosaurSizes, 3, 3)
'
'Seismosaurus: up to 40 meters long.
'Mamenchisaurus: up to 22 meters long.
'Coelophysis: up to 3 meters long.
'Caudipteryx: up to 1 meters long.
'Cetiosaurus: up to 18 meters long.
'Chasmosaurus: up to 5 meters long.
'
'Sort(dinosaurs, dinosaurSizes, 3, 3, rc)
'
'Seismosaurus: up to 40 meters long.
'Mamenchisaurus: up to 22 meters long.
'Coelophysis: up to 3 meters long.
'Chasmosaurus: up to 5 meters long.
'Cetiosaurus: up to 18 meters long.
'Caudipteryx: up to 1 meters long.

Remarks

Each key in the keysArray has a corresponding item in the itemsArray. When a key is repositioned during the sorting, the corresponding item in the itemsArray is similarly repositioned. Therefore, the itemsArray is sorted according to the arrangement of the corresponding keys in the keysArray.

If comparer is null, each key within the specified range of elements in the keysArray must implement the IComparable<T> generic interface to be capable of comparisons with every other key.

You can sort if there are more items than keys, but the items that have no corresponding keys will not be sorted. You cannot sort if there are more keys than items; doing this throws an ArgumentException.

If the sort is not successfully completed, the results are undefined.

This method uses the introspective sort (introsort) algorithm as follows:

  • If the partition size is fewer than 16 elements, it uses an insertion sort algorithm.

  • If the number of partitions exceeds 2 * LogN, where N is the range of the input array, it uses a Heapsort algorithm.

  • Otherwise, it uses a Quicksort algorithm.

This implementation performs an unstable sort; that is, if two elements are equal, their order might not be preserved. In contrast, a stable sort preserves the order of elements that are equal.

For arrays that are sorted by using the Heapsort and Quicksort algorithms, in the worst case, this method is an O(n log n) operation, where n is length.

Notes to Callers

The .NET Framework 4 and earlier versions used only the Quicksort algorithm. Quicksort identifies invalid comparers in some situations in which the sorting operation throws an IndexOutOfRangeException exception, and throws an ArgumentException exception to the caller. Starting with the .NET Framework 4.5, it is possible that sorting operations that previously threw ArgumentException will not throw an exception, because the insertion sort and heapsort algorithms do not detect an invalid comparer. For the most part, this applies to arrays with fewer than 16 elements.

See also

Applies to