ArrayList.Reverse 方法

定义

ArrayList 或它的一部分中元素的顺序反转。Reverses the order of the elements in the ArrayList or a portion of it.

重载

Reverse()

将整个 ArrayList 中元素的顺序反转。Reverses the order of the elements in the entire ArrayList.

Reverse(Int32, Int32)

将指定范围中元素的顺序反转。Reverses the order of the elements in the specified range.

Reverse()

将整个 ArrayList 中元素的顺序反转。Reverses the order of the elements in the entire ArrayList.

public:
 virtual void Reverse();
public virtual void Reverse ();
abstract member Reverse : unit -> unit
override this.Reverse : unit -> unit
Public Overridable Sub Reverse ()

例外

ArrayList 为只读。The ArrayList is read-only.

示例

下面的代码示例演示如何反转中的值的排序顺序 ArrayListThe following code example shows how to reverse the sort order of the values in an ArrayList.

using namespace System;
using namespace System::Collections;
void PrintValues( IEnumerable^ myList );
int main()
{
   
   // Creates and initializes a new ArrayList.
   ArrayList^ myAL = gcnew ArrayList;
   myAL->Add( "The" );
   myAL->Add( "quick" );
   myAL->Add( "brown" );
   myAL->Add( "fox" );
   myAL->Add( "jumps" );
   myAL->Add( "over" );
   myAL->Add( "the" );
   myAL->Add( "lazy" );
   myAL->Add( "dog" );
   
   // Displays the values of the ArrayList.
   Console::WriteLine( "The ArrayList initially contains the following values:" );
   PrintValues( myAL );
   
   // Reverses the sort order of the values of the ArrayList.
   myAL->Reverse();
   
   // Displays the values of the ArrayList.
   Console::WriteLine( "After reversing:" );
   PrintValues( myAL );
}

void PrintValues( IEnumerable^ myList )
{
   IEnumerator^ myEnum = myList->GetEnumerator();
   while ( myEnum->MoveNext() )
   {
      Object^ obj = safe_cast<Object^>(myEnum->Current);
      Console::WriteLine( "   {0}", obj );
   }

   Console::WriteLine();
}

/* 
 This code produces the following output.
 
 The ArrayList initially contains the following values:
    The
    quick
    brown
    fox
    jumps
    over
    the
    lazy
    dog

 After reversing:
    dog
    lazy
    the
    over
    jumps
    fox
    brown
    quick
    The
 */
using System;
using System.Collections;
public class SamplesArrayList  {

   public static void Main()  {

      // Creates and initializes a new ArrayList.
      ArrayList myAL = new ArrayList();
      myAL.Add( "The" );
      myAL.Add( "quick" );
      myAL.Add( "brown" );
      myAL.Add( "fox" );
      myAL.Add( "jumps" );
      myAL.Add( "over" );
      myAL.Add( "the" );
      myAL.Add( "lazy" );
      myAL.Add( "dog" );

      // Displays the values of the ArrayList.
      Console.WriteLine( "The ArrayList initially contains the following values:" );
      PrintValues( myAL );

      // Reverses the sort order of the values of the ArrayList.
      myAL.Reverse();

      // Displays the values of the ArrayList.
      Console.WriteLine( "After reversing:" );
      PrintValues( myAL );
   }

   public static void PrintValues( IEnumerable myList )  {
      foreach ( Object obj in myList )
         Console.WriteLine( "   {0}", obj );
      Console.WriteLine();
   }
}


/*
This code produces the following output.

The ArrayList initially contains the following values:
   The
   quick
   brown
   fox
   jumps
   over
   the
   lazy
   dog

After reversing:
   dog
   lazy
   the
   over
   jumps
   fox
   brown
   quick
   The
*/
Imports System.Collections

Public Class SamplesArrayList    
    
    Public Shared Sub Main()
        
        ' Creates and initializes a new ArrayList.
        Dim myAL As New ArrayList()
        myAL.Add("The")
        myAL.Add("quick")
        myAL.Add("brown")
        myAL.Add("fox")
        myAL.Add("jumps")
        myAL.Add("over")
        myAL.Add("the")
        myAL.Add("lazy")
        myAL.Add("dog")
        
        ' Displays the values of the ArrayList.
        Console.WriteLine("The ArrayList initially contains the " _
           + "following values:")
        PrintValues(myAL)
        
        ' Reverses the sort order of the values of the ArrayList.
        myAL.Reverse()
        
        ' Displays the values of the ArrayList.
        Console.WriteLine("After reversing:")
        PrintValues(myAL)
    End Sub
    
    Public Shared Sub PrintValues(myList As IEnumerable)
        Dim obj As [Object]
        For Each obj In  myList
            Console.WriteLine("   {0}", obj)
        Next obj
        Console.WriteLine()
    End Sub

End Class


' This code produces the following output.
' 
' The ArrayList initially contains the following values:
'    The
'    quick
'    brown
'    fox
'    jumps
'    over
'    the
'    lazy
'    dog
'
' After reversing:
'    dog
'    lazy
'    the
'    over
'    jumps
'    fox
'    brown
'    quick
'    The

注解

此方法使用 Array.Reverse 反转元素的顺序,以便 [i] 处的元素( ArrayList 其中 i 是该范围内的任何索引)移动到 ArrayList [j],其中 j 等于 index + index + count -i-1。This method uses Array.Reverse to reverse the order of the elements, such that the element at ArrayList [i], where i is any index within the range, moves to ArrayList [j], where j equals index + index + count - i - 1.

此方法是一个 O(n) 操作,其中 nCountThis method is an O(n) operation, where n is Count.

适用于

Reverse(Int32, Int32)

将指定范围中元素的顺序反转。Reverses the order of the elements in the specified range.

public:
 virtual void Reverse(int index, int count);
public virtual void Reverse (int index, int count);
abstract member Reverse : int * int -> unit
override this.Reverse : int * int -> unit
Public Overridable Sub Reverse (index As Integer, count As Integer)

参数

index
Int32

要反转的范围的从零开始的起始索引。The zero-based starting index of the range to reverse.

count
Int32

要反转的范围内的元素数。The number of elements in the range to reverse.

例外

index 小于零。index is less than zero.

- 或 --or- count 小于零。count is less than zero.

indexcount 不表示 ArrayList 中元素的有效范围。index and count do not denote a valid range of elements in the ArrayList.

ArrayList 为只读。The ArrayList is read-only.

示例

下面的代码示例演示如何反转中某个范围内的值的排序顺序 ArrayListThe following code example shows how to reverse the sort order of the values in a range of elements in an ArrayList.

using namespace System;
using namespace System::Collections;
void PrintValues( IEnumerable^ myList );
int main()
{
   
   // Creates and initializes a new ArrayList.
   ArrayList^ myAL = gcnew ArrayList;
   myAL->Add( "The" );
   myAL->Add( "QUICK" );
   myAL->Add( "BROWN" );
   myAL->Add( "FOX" );
   myAL->Add( "jumps" );
   myAL->Add( "over" );
   myAL->Add( "the" );
   myAL->Add( "lazy" );
   myAL->Add( "dog" );
   
   // Displays the values of the ArrayList.
   Console::WriteLine( "The ArrayList initially contains the following values:" );
   PrintValues( myAL );
   
   // Reverses the sort order of the values of the ArrayList.
   myAL->Reverse( 1, 3 );
   
   // Displays the values of the ArrayList.
   Console::WriteLine( "After reversing:" );
   PrintValues( myAL );
}

void PrintValues( IEnumerable^ myList )
{
   IEnumerator^ myEnum = myList->GetEnumerator();
   while ( myEnum->MoveNext() )
   {
      Object^ obj = safe_cast<Object^>(myEnum->Current);
      Console::WriteLine( "   {0}", obj );
   }

   Console::WriteLine();
}

/* 
 This code produces the following output.
 
 The ArrayList initially contains the following values:
    The
    QUICK
    BROWN
    FOX
    jumps
    over
    the
    lazy
    dog

 After reversing:
    The
    FOX
    BROWN
    QUICK
    jumps
    over
    the
    lazy
    dog

 */
using System;
using System.Collections;
public class SamplesArrayList  {

   public static void Main()  {

      // Creates and initializes a new ArrayList.
      ArrayList myAL = new ArrayList();
      myAL.Add( "The" );
      myAL.Add( "QUICK" );
      myAL.Add( "BROWN" );
      myAL.Add( "FOX" );
      myAL.Add( "jumps" );
      myAL.Add( "over" );
      myAL.Add( "the" );
      myAL.Add( "lazy" );
      myAL.Add( "dog" );

      // Displays the values of the ArrayList.
      Console.WriteLine( "The ArrayList initially contains the following values:" );
      PrintValues( myAL );

      // Reverses the sort order of the values of the ArrayList.
      myAL.Reverse( 1, 3 );

      // Displays the values of the ArrayList.
      Console.WriteLine( "After reversing:" );
      PrintValues( myAL );
   }

   public static void PrintValues( IEnumerable myList )  {
      foreach ( Object obj in myList )
         Console.WriteLine( "   {0}", obj );
      Console.WriteLine();
   }
}


/*
This code produces the following output.

The ArrayList initially contains the following values:
   The
   QUICK
   BROWN
   FOX
   jumps
   over
   the
   lazy
   dog

After reversing:
   The
   FOX
   BROWN
   QUICK
   jumps
   over
   the
   lazy
   dog

*/
Imports System.Collections

Public Class SamplesArrayList

    Public Shared Sub Main()

        ' Creates and initializes a new ArrayList.
        Dim myAL As New ArrayList()
        myAL.Add("The")
        myAL.Add("QUICK")
        myAL.Add("BROWN")
        myAL.Add("FOX")
        myAL.Add("jumps")
        myAL.Add("over")
        myAL.Add("the")
        myAL.Add("lazy")
        myAL.Add("dog")

        ' Displays the values of the ArrayList.
        Console.WriteLine("The ArrayList initially contains the following values:")
        PrintValues(myAL)

        ' Reverses the sort order of the values of the ArrayList.
        myAL.Reverse(1, 3)

        ' Displays the values of the ArrayList.
        Console.WriteLine("After reversing:")
        PrintValues(myAL)

    End Sub

    Public Shared Sub PrintValues(myList As IEnumerable)
        Dim obj As [Object]
        For Each obj In  myList
            Console.WriteLine("   {0}", obj)
        Next obj
        Console.WriteLine()
    End Sub

End Class


' This code produces the following output.
' 
' The ArrayList initially contains the following values:
'    The
'    QUICK
'    BROWN
'    FOX
'    jumps
'    over
'    the
'    lazy
'    dog
'
' After reversing:
'    The
'    FOX
'    BROWN
'    QUICK
'    jumps
'    over
'    the
'    lazy
'    dog


注解

此方法使用 Array.Reverse 反转元素的顺序,以便 [i] 处的元素( ArrayList 其中 i 是该范围内的任何索引)移动到 ArrayList [j],其中 j 等于 index + index + count -i-1。This method uses Array.Reverse to reverse the order of the elements, such that the element at ArrayList [i], where i is any index within the range, moves to ArrayList [j], where j equals index + index + count - i - 1.

此方法是一个 O(n) 操作,其中 ncountThis method is an O(n) operation, where n is count.

适用于