Array.LastIndexOf Method

Definition

傳回一維 ArrayArray 的某部分中數值的最後一個相符項目索引。Returns the index of the last occurrence of a value in a one-dimensional Array or in a portion of the Array.

Overloads

LastIndexOf(Array, Object)

搜尋指定物件,並且傳回整個一維 Array 中最後一個相符項目的索引。Searches for the specified object and returns the index of the last occurrence within the entire one-dimensional Array.

LastIndexOf(Array, Object, Int32)

搜尋指定的物件,並傳回一維 Array 內從第一個項目延伸至指定之索引的項目範圍中,最後一個相符項目的索引。Searches for the specified object and returns the index of the last occurrence within the range of elements in the one-dimensional Array that extends from the first element to the specified index.

LastIndexOf(Array, Object, Int32, Int32)

搜尋指定的物件,並傳回一維 Array 中包含指定之項目數且結束於指定之索引的項目範圍內,最後一個相符項目的索引。Searches for the specified object and returns the index of the last occurrence within the range of elements in the one-dimensional Array that contains the specified number of elements and ends at the specified index.

LastIndexOf<T>(T[], T)

搜尋指定的物件,並傳回整個 Array 中最後一個相符項目的索引。Searches for the specified object and returns the index of the last occurrence within the entire Array.

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

Array 中從第一個項目開始到指定的索引這段範圍的項目內,搜尋指定的物件最後一次出現的位置,並傳回其索引值 (索引以零為起始)。Searches for the specified object and returns the index of the last occurrence within the range of elements in the Array that extends from the first element to the specified index.

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

搜尋指定的物件,並傳回 Array 中包含指定之項目數且結束於指定之索引的項目範圍內,最後一個相符項目的索引。Searches for the specified object and returns the index of the last occurrence within the range of elements in the Array that contains the specified number of elements and ends at the specified index.

LastIndexOf(Array, Object)

搜尋指定物件,並且傳回整個一維 Array 中最後一個相符項目的索引。Searches for the specified object and returns the index of the last occurrence within the entire one-dimensional Array.

public:
 static int LastIndexOf(Array ^ array, System::Object ^ value);
public static int LastIndexOf (Array array, object value);
static member LastIndexOf : Array * obj -> int
Public Shared Function LastIndexOf (array As Array, value As Object) As Integer

Parameters

array
Array

要搜尋的一維 ArrayThe one-dimensional Array to search.

value
Object

要在 array 中尋找的物件。The object to locate in array.

Returns

Int32

如有找到,則為整個 arrayvalue 最後一個相符項目的索引,否則為陣列的下限減 1。The index of the last occurrence of value within the entire array, if found; otherwise, the lower bound of the array minus 1.

Exceptions

arraynullarray is null.

array 是多維度。array is multidimensional.

Examples

下列程式碼範例顯示如何判斷陣列中指定專案最後一次出現的索引。The following code example shows how to determine the index of the last occurrence of a specified element in an array.

using namespace System;
void PrintIndexAndValues( Array^ myArray );

void main()
{
   // Creates and initializes a new Array instance with three elements of the same value.
   Array^ myArray = Array::CreateInstance( String::typeid, 12 );
   myArray->SetValue( "the", 0 );
   myArray->SetValue( "quick", 1 );
   myArray->SetValue( "brown", 2 );
   myArray->SetValue( "fox", 3 );
   myArray->SetValue( "jumps", 4 );
   myArray->SetValue( "over", 5 );
   myArray->SetValue( "the", 6 );
   myArray->SetValue( "lazy", 7 );
   myArray->SetValue( "dog", 8 );
   myArray->SetValue( "in", 9 );
   myArray->SetValue( "the", 10 );
   myArray->SetValue( "barn", 11 );

   // Displays the values of the Array.
   Console::WriteLine(  "The Array instance contains the following values:" );
   PrintIndexAndValues( myArray );

   // Searches for the last occurrence of the duplicated value.
   String^ myString =  "the";
   int myIndex = Array::LastIndexOf( myArray, myString );
   Console::WriteLine(  "The last occurrence of \"{0}\" is at index {1}.", myString, myIndex );

   // Searches for the last occurrence of the duplicated value in the first section of the Array.
   myIndex = Array::LastIndexOf( myArray, myString, 8 );
   Console::WriteLine(  "The last occurrence of \"{0}\" between the start and index 8 is at index {1}.", myString, myIndex );

   // Searches for the last occurrence of the duplicated value in a section of the Array.  
   // Note that the start index is greater than the end index because the search is done backward.
   myIndex = Array::LastIndexOf( myArray, myString, 10, 6 );
   Console::WriteLine(  "The last occurrence of \"{0}\" between index 5 and index 10 is at index {1}.", myString, myIndex );
}

void PrintIndexAndValues( Array^ myArray )
{
   for ( int i = myArray->GetLowerBound( 0 ); i <= myArray->GetUpperBound( 0 ); i++ )
      Console::WriteLine(  "\t[{0}]:\t{1}", i, myArray->GetValue( i ) );
}

/* 
 This code produces the following output.
 
 The Array instance contains the following values:
     [0]:    the
     [1]:    quick
     [2]:    brown
     [3]:    fox
     [4]:    jumps
     [5]:    over
     [6]:    the
     [7]:    lazy
     [8]:    dog
     [9]:    in
     [10]:    the
     [11]:    barn
 The last occurrence of "the" is at index 10.
 The last occurrence of "the" between the start and index 8 is at index 6.
 The last occurrence of "the" between index 5 and index 10 is at index 10.
 */
// Creates and initializes a new Array with three elements of the same value.
Array myArray=Array.CreateInstance( typeof(String), 12 );
myArray.SetValue( "the", 0 );
myArray.SetValue( "quick", 1 );
myArray.SetValue( "brown", 2 );
myArray.SetValue( "fox", 3 );
myArray.SetValue( "jumps", 4 );
myArray.SetValue( "over", 5 );
myArray.SetValue( "the", 6 );
myArray.SetValue( "lazy", 7 );
myArray.SetValue( "dog", 8 );
myArray.SetValue( "in", 9 );
myArray.SetValue( "the", 10 );
myArray.SetValue( "barn", 11 );

// Displays the values of the Array.
Console.WriteLine( "The Array contains the following values:" );
PrintIndexAndValues( myArray );

// Searches for the last occurrence of the duplicated value.
String myString = "the";
int myIndex = Array.LastIndexOf( myArray, myString );
Console.WriteLine( "The last occurrence of \"{0}\" is at index {1}.", myString, myIndex );

// Searches for the last occurrence of the duplicated value in the first section of the Array.
myIndex = Array.LastIndexOf( myArray, myString, 8 );
Console.WriteLine( "The last occurrence of \"{0}\" between the start and index 8 is at index {1}.", myString, myIndex );

// Searches for the last occurrence of the duplicated value in a section of the Array.
// Note that the start index is greater than the end index because the search is done backward.
myIndex = Array.LastIndexOf( myArray, myString, 10, 6 );
Console.WriteLine( "The last occurrence of \"{0}\" between index 5 and index 10 is at index {1}.", myString, myIndex );

void PrintIndexAndValues( Array anArray )  {
   for ( int i = anArray.GetLowerBound(0); i <= anArray.GetUpperBound(0); i++ )
      Console.WriteLine( "\t[{0}]:\t{1}", i, anArray.GetValue( i ) );
}

/*
This code produces the following output.

The Array contains the following values:
   [0]:    the
   [1]:    quick
   [2]:    brown
   [3]:    fox
   [4]:    jumps
   [5]:    over
   [6]:    the
   [7]:    lazy
   [8]:    dog
   [9]:    in
   [10]:    the
   [11]:    barn
The last occurrence of "the" is at index 10.
The last occurrence of "the" between the start and index 8 is at index 6.
The last occurrence of "the" between index 5 and index 10 is at index 10.
*/
Public Class SamplesArray    
    
    Public Shared Sub Main()
        
        ' Creates and initializes a new Array with three elements of
        ' the same value.
        Dim myArray As Array = Array.CreateInstance(GetType(String), 12)
        myArray.SetValue("the", 0)
        myArray.SetValue("quick", 1)
        myArray.SetValue("brown", 2)
        myArray.SetValue("fox", 3)
        myArray.SetValue("jumps", 4)
        myArray.SetValue("over", 5)
        myArray.SetValue("the", 6)
        myArray.SetValue("lazy", 7)
        myArray.SetValue("dog", 8)
        myArray.SetValue("in", 9)
        myArray.SetValue("the", 10)
        myArray.SetValue("barn", 11)
        
        ' Displays the values of the Array.
        Console.WriteLine("The Array contains the following values:")
        PrintIndexAndValues(myArray)
        
        ' Searches for the last occurrence of the duplicated value.
        Dim myString As String = "the"
        Dim myIndex As Integer = Array.LastIndexOf(myArray, myString)
        Console.WriteLine("The last occurrence of ""{0}"" is at index {1}.", _
           myString, myIndex)
        
        ' Searches for the last occurrence of the duplicated value in the first
        ' section of the Array.
        myIndex = Array.LastIndexOf(myArray, myString, 8)
        Console.WriteLine("The last occurrence of ""{0}"" between the start " _
           + "and index 8 is at index {1}.", myString, myIndex)
        
        ' Searches for the last occurrence of the duplicated value in a section
        ' of the Array.  Note that the start index is greater than the end
        ' index because the search is done backward.
        myIndex = Array.LastIndexOf(myArray, myString, 10, 6)
        Console.WriteLine("The last occurrence of ""{0}"" between index 5 " _
           + "and index 10 is at index {1}.", myString, myIndex)
    End Sub
    
    
    Public Shared Sub PrintIndexAndValues(myArray As Array)
        Dim i As Integer
        For i = myArray.GetLowerBound(0) To myArray.GetUpperBound(0)
            Console.WriteLine(ControlChars.Tab + "[{0}]:" + ControlChars.Tab _
               + "{1}", i, myArray.GetValue(i))
        Next i
    End Sub
End Class

' This code produces the following output.
' 
' The Array contains the following values:
'     [0]:    the
'     [1]:    quick
'     [2]:    brown
'     [3]:    fox
'     [4]:    jumps
'     [5]:    over
'     [6]:    the
'     [7]:    lazy
'     [8]:    dog
'     [9]:    in
'     [10]:    the
'     [11]:    barn
' The last occurrence of "the" is at index 10.
' The last occurrence of "the" between the start and index 8 is at index 6.
' The last occurrence of "the" between index 5 and index 10 is at index 10. 

Remarks

一維 Array 會從最後一個元素開始搜尋,並在第一個元素結束。The one-dimensional Array is searched backward starting at the last element and ending at the first element.

使用 Object.Equals 方法,將元素與指定的值進行比較。The elements are compared to the specified value using the Object.Equals method. 如果元素類型是 nonintrinsic (使用者定義的)類型,則會使用該類型的 Equals 實作為。If the element type is a nonintrinsic (user-defined) type, the Equals implementation of that type is used.

因為大部分陣列的下限都是零,所以當找不到 value 時,這個方法通常會傳回-1。Since most arrays will have a lower bound of zero, this method would generally return -1 when value is not found. 在陣列下限等於 Int32.MinValue 且找不到 value 的罕見情況下,這個方法會傳回 Int32.MaxValue,這是 System.Int32.MinValue - 1In the rare case that the lower bound of the array is equal to Int32.MinValue and value is not found, this method returns Int32.MaxValue, which is System.Int32.MinValue - 1.

這個方法是 O (n)運算,其中 narrayLengthThis method is an O(n) operation, where n is the Length of array.

在 .NET Framework 版本2.0 中,這個方法會使用 ArrayEqualsCompareTo 方法,來判斷 Object 參數所指定的 value 是否存在。In the .NET Framework version 2.0, this method uses the Equals and CompareTo methods of the Array to determine whether the Object specified by the value parameter exists. 在舊版的 .NET Framework 中,這項決定是使用 valueObject 本身的 EqualsCompareTo 方法進行。In the earlier versions of the .NET Framework, this determination was made by using the Equals and CompareTo methods of the valueObject itself.

在集合中的物件上,item 參數的 CompareTo 方法。CompareTo methods of the item parameter on the objects in the collection.

See also

LastIndexOf(Array, Object, Int32)

搜尋指定的物件,並傳回一維 Array 內從第一個項目延伸至指定之索引的項目範圍中,最後一個相符項目的索引。Searches for the specified object and returns the index of the last occurrence within the range of elements in the one-dimensional Array that extends from the first element to the specified index.

public:
 static int LastIndexOf(Array ^ array, System::Object ^ value, int startIndex);
public static int LastIndexOf (Array array, object value, int startIndex);
static member LastIndexOf : Array * obj * int -> int
Public Shared Function LastIndexOf (array As Array, value As Object, startIndex As Integer) As Integer

Parameters

array
Array

要搜尋的一維 ArrayThe one-dimensional Array to search.

value
Object

要在 array 中尋找的物件。The object to locate in array.

startIndex
Int32

反向搜尋的起始索引。The starting index of the backward search.

Returns

Int32

如有找到,則為 array 中從第一個項目延伸到 startIndex 的項目範圍內,value 的最後一個相符項目的索引,否則為陣列的下限減 1。The index of the last occurrence of value within the range of elements in array that extends from the first element to startIndex, if found; otherwise, the lower bound of the array minus 1.

Exceptions

arraynullarray is null.

startIndex 超出 array 的有效索引範圍。startIndex is outside the range of valid indexes for array.

array 是多維度。array is multidimensional.

Examples

下列程式碼範例顯示如何判斷陣列中指定專案最後一次出現的索引。The following code example shows how to determine the index of the last occurrence of a specified element in an array.

using namespace System;
void PrintIndexAndValues( Array^ myArray );

void main()
{
   // Creates and initializes a new Array instance with three elements of the same value.
   Array^ myArray = Array::CreateInstance( String::typeid, 12 );
   myArray->SetValue( "the", 0 );
   myArray->SetValue( "quick", 1 );
   myArray->SetValue( "brown", 2 );
   myArray->SetValue( "fox", 3 );
   myArray->SetValue( "jumps", 4 );
   myArray->SetValue( "over", 5 );
   myArray->SetValue( "the", 6 );
   myArray->SetValue( "lazy", 7 );
   myArray->SetValue( "dog", 8 );
   myArray->SetValue( "in", 9 );
   myArray->SetValue( "the", 10 );
   myArray->SetValue( "barn", 11 );

   // Displays the values of the Array.
   Console::WriteLine(  "The Array instance contains the following values:" );
   PrintIndexAndValues( myArray );

   // Searches for the last occurrence of the duplicated value.
   String^ myString =  "the";
   int myIndex = Array::LastIndexOf( myArray, myString );
   Console::WriteLine(  "The last occurrence of \"{0}\" is at index {1}.", myString, myIndex );

   // Searches for the last occurrence of the duplicated value in the first section of the Array.
   myIndex = Array::LastIndexOf( myArray, myString, 8 );
   Console::WriteLine(  "The last occurrence of \"{0}\" between the start and index 8 is at index {1}.", myString, myIndex );

   // Searches for the last occurrence of the duplicated value in a section of the Array.  
   // Note that the start index is greater than the end index because the search is done backward.
   myIndex = Array::LastIndexOf( myArray, myString, 10, 6 );
   Console::WriteLine(  "The last occurrence of \"{0}\" between index 5 and index 10 is at index {1}.", myString, myIndex );
}

void PrintIndexAndValues( Array^ myArray )
{
   for ( int i = myArray->GetLowerBound( 0 ); i <= myArray->GetUpperBound( 0 ); i++ )
      Console::WriteLine(  "\t[{0}]:\t{1}", i, myArray->GetValue( i ) );
}

/* 
 This code produces the following output.
 
 The Array instance contains the following values:
     [0]:    the
     [1]:    quick
     [2]:    brown
     [3]:    fox
     [4]:    jumps
     [5]:    over
     [6]:    the
     [7]:    lazy
     [8]:    dog
     [9]:    in
     [10]:    the
     [11]:    barn
 The last occurrence of "the" is at index 10.
 The last occurrence of "the" between the start and index 8 is at index 6.
 The last occurrence of "the" between index 5 and index 10 is at index 10.
 */
// Creates and initializes a new Array with three elements of the same value.
Array myArray=Array.CreateInstance( typeof(String), 12 );
myArray.SetValue( "the", 0 );
myArray.SetValue( "quick", 1 );
myArray.SetValue( "brown", 2 );
myArray.SetValue( "fox", 3 );
myArray.SetValue( "jumps", 4 );
myArray.SetValue( "over", 5 );
myArray.SetValue( "the", 6 );
myArray.SetValue( "lazy", 7 );
myArray.SetValue( "dog", 8 );
myArray.SetValue( "in", 9 );
myArray.SetValue( "the", 10 );
myArray.SetValue( "barn", 11 );

// Displays the values of the Array.
Console.WriteLine( "The Array contains the following values:" );
PrintIndexAndValues( myArray );

// Searches for the last occurrence of the duplicated value.
String myString = "the";
int myIndex = Array.LastIndexOf( myArray, myString );
Console.WriteLine( "The last occurrence of \"{0}\" is at index {1}.", myString, myIndex );

// Searches for the last occurrence of the duplicated value in the first section of the Array.
myIndex = Array.LastIndexOf( myArray, myString, 8 );
Console.WriteLine( "The last occurrence of \"{0}\" between the start and index 8 is at index {1}.", myString, myIndex );

// Searches for the last occurrence of the duplicated value in a section of the Array.
// Note that the start index is greater than the end index because the search is done backward.
myIndex = Array.LastIndexOf( myArray, myString, 10, 6 );
Console.WriteLine( "The last occurrence of \"{0}\" between index 5 and index 10 is at index {1}.", myString, myIndex );

void PrintIndexAndValues( Array anArray )  {
   for ( int i = anArray.GetLowerBound(0); i <= anArray.GetUpperBound(0); i++ )
      Console.WriteLine( "\t[{0}]:\t{1}", i, anArray.GetValue( i ) );
}

/*
This code produces the following output.

The Array contains the following values:
   [0]:    the
   [1]:    quick
   [2]:    brown
   [3]:    fox
   [4]:    jumps
   [5]:    over
   [6]:    the
   [7]:    lazy
   [8]:    dog
   [9]:    in
   [10]:    the
   [11]:    barn
The last occurrence of "the" is at index 10.
The last occurrence of "the" between the start and index 8 is at index 6.
The last occurrence of "the" between index 5 and index 10 is at index 10.
*/
Public Class SamplesArray    
    
    Public Shared Sub Main()
        
        ' Creates and initializes a new Array with three elements of
        ' the same value.
        Dim myArray As Array = Array.CreateInstance(GetType(String), 12)
        myArray.SetValue("the", 0)
        myArray.SetValue("quick", 1)
        myArray.SetValue("brown", 2)
        myArray.SetValue("fox", 3)
        myArray.SetValue("jumps", 4)
        myArray.SetValue("over", 5)
        myArray.SetValue("the", 6)
        myArray.SetValue("lazy", 7)
        myArray.SetValue("dog", 8)
        myArray.SetValue("in", 9)
        myArray.SetValue("the", 10)
        myArray.SetValue("barn", 11)
        
        ' Displays the values of the Array.
        Console.WriteLine("The Array contains the following values:")
        PrintIndexAndValues(myArray)
        
        ' Searches for the last occurrence of the duplicated value.
        Dim myString As String = "the"
        Dim myIndex As Integer = Array.LastIndexOf(myArray, myString)
        Console.WriteLine("The last occurrence of ""{0}"" is at index {1}.", _
           myString, myIndex)
        
        ' Searches for the last occurrence of the duplicated value in the first
        ' section of the Array.
        myIndex = Array.LastIndexOf(myArray, myString, 8)
        Console.WriteLine("The last occurrence of ""{0}"" between the start " _
           + "and index 8 is at index {1}.", myString, myIndex)
        
        ' Searches for the last occurrence of the duplicated value in a section
        ' of the Array.  Note that the start index is greater than the end
        ' index because the search is done backward.
        myIndex = Array.LastIndexOf(myArray, myString, 10, 6)
        Console.WriteLine("The last occurrence of ""{0}"" between index 5 " _
           + "and index 10 is at index {1}.", myString, myIndex)
    End Sub
    
    
    Public Shared Sub PrintIndexAndValues(myArray As Array)
        Dim i As Integer
        For i = myArray.GetLowerBound(0) To myArray.GetUpperBound(0)
            Console.WriteLine(ControlChars.Tab + "[{0}]:" + ControlChars.Tab _
               + "{1}", i, myArray.GetValue(i))
        Next i
    End Sub
End Class

' This code produces the following output.
' 
' The Array contains the following values:
'     [0]:    the
'     [1]:    quick
'     [2]:    brown
'     [3]:    fox
'     [4]:    jumps
'     [5]:    over
'     [6]:    the
'     [7]:    lazy
'     [8]:    dog
'     [9]:    in
'     [10]:    the
'     [11]:    barn
' The last occurrence of "the" is at index 10.
' The last occurrence of "the" between the start and index 8 is at index 6.
' The last occurrence of "the" between index 5 and index 10 is at index 10. 

Remarks

一維 Array 會從 startIndex 開始向前搜尋,並在第一個元素結束。The one-dimensional Array is searched backward starting at startIndex and ending at the first element.

使用 Object.Equals 方法,將元素與指定的值進行比較。The elements are compared to the specified value using the Object.Equals method. 如果元素類型是 nonintrinsic (使用者定義的)類型,則會使用該類型的 Equals 實作為。If the element type is a nonintrinsic (user-defined) type, the Equals implementation of that type is used.

因為大部分陣列的下限都是零,所以當找不到 value 時,這個方法通常會傳回-1。Since most arrays will have a lower bound of zero, this method would generally return -1 when value is not found. 在陣列下限等於 Int32.MinValue 且找不到 value 的罕見情況下,這個方法會傳回 Int32.MaxValue,這是 System.Int32.MinValue - 1In the rare case that the lower bound of the array is equal to Int32.MinValue and value is not found, this method returns Int32.MaxValue, which is System.Int32.MinValue - 1.

這個方法是 O (n)運算,其中 n 是從 array 開頭到 startIndex的元素數目。This method is an O(n) operation, where n is the number of elements from the beginning of array to startIndex.

在 .NET Framework 版本2.0 中,這個方法會使用 ArrayEqualsCompareTo 方法,來判斷 Object 參數所指定的 value 是否存在。In the .NET Framework version 2.0, this method uses the Equals and CompareTo methods of the Array to determine whether the Object specified by the value parameter exists. 在舊版的 .NET Framework 中,這項決定是使用 valueObject 本身的 EqualsCompareTo 方法進行。In the earlier versions of the .NET Framework, this determination was made by using the Equals and CompareTo methods of the valueObject itself.

See also

LastIndexOf(Array, Object, Int32, Int32)

搜尋指定的物件,並傳回一維 Array 中包含指定之項目數且結束於指定之索引的項目範圍內,最後一個相符項目的索引。Searches for the specified object and returns the index of the last occurrence within the range of elements in the one-dimensional Array that contains the specified number of elements and ends at the specified index.

public:
 static int LastIndexOf(Array ^ array, System::Object ^ value, int startIndex, int count);
public static int LastIndexOf (Array array, object value, int startIndex, int count);
static member LastIndexOf : Array * obj * int * int -> int
Public Shared Function LastIndexOf (array As Array, value As Object, startIndex As Integer, count As Integer) As Integer

Parameters

array
Array

要搜尋的一維 ArrayThe one-dimensional Array to search.

value
Object

要在 array 中尋找的物件。The object to locate in array.

startIndex
Int32

反向搜尋的起始索引。The starting index of the backward search.

count
Int32

區段中要搜尋的項目數目。The number of elements in the section to search.

Returns

Int32

如有找到,則為在 array 中包含 count 內指定之項目數且結束於 startIndex 的項目範圍內,value 的最後一個相符項目之索引,否則為陣列的下限減 1。The index of the last occurrence of value within the range of elements in array that contains the number of elements specified in count and ends at startIndex, if found; otherwise, the lower bound of the array minus 1.

Exceptions

arraynullarray is null.

startIndex 超出 array 的有效索引範圍。startIndex is outside the range of valid indexes for array.

-或--or- count 小於零。count is less than zero.

-或--or- startIndexcount 不指定 array 的有效區段。startIndex and count do not specify a valid section in array.

array 是多維度。array is multidimensional.

Examples

下列程式碼範例顯示如何判斷陣列中指定專案最後一次出現的索引。The following code example shows how to determine the index of the last occurrence of a specified element in an array. 請注意,LastIndexOf 方法是向後搜尋;因此,count 必須小於或等於(startIndex 減去陣列的下限加1)。Note that the LastIndexOf method is a backward search; therefore, count must be less than or equal to (startIndex minus the lower bound of the array plus 1).

using namespace System;
void PrintIndexAndValues( Array^ myArray );

void main()
{
   // Creates and initializes a new Array instance with three elements of the same value.
   Array^ myArray = Array::CreateInstance( String::typeid, 12 );
   myArray->SetValue( "the", 0 );
   myArray->SetValue( "quick", 1 );
   myArray->SetValue( "brown", 2 );
   myArray->SetValue( "fox", 3 );
   myArray->SetValue( "jumps", 4 );
   myArray->SetValue( "over", 5 );
   myArray->SetValue( "the", 6 );
   myArray->SetValue( "lazy", 7 );
   myArray->SetValue( "dog", 8 );
   myArray->SetValue( "in", 9 );
   myArray->SetValue( "the", 10 );
   myArray->SetValue( "barn", 11 );

   // Displays the values of the Array.
   Console::WriteLine(  "The Array instance contains the following values:" );
   PrintIndexAndValues( myArray );

   // Searches for the last occurrence of the duplicated value.
   String^ myString =  "the";
   int myIndex = Array::LastIndexOf( myArray, myString );
   Console::WriteLine(  "The last occurrence of \"{0}\" is at index {1}.", myString, myIndex );

   // Searches for the last occurrence of the duplicated value in the first section of the Array.
   myIndex = Array::LastIndexOf( myArray, myString, 8 );
   Console::WriteLine(  "The last occurrence of \"{0}\" between the start and index 8 is at index {1}.", myString, myIndex );

   // Searches for the last occurrence of the duplicated value in a section of the Array.  
   // Note that the start index is greater than the end index because the search is done backward.
   myIndex = Array::LastIndexOf( myArray, myString, 10, 6 );
   Console::WriteLine(  "The last occurrence of \"{0}\" between index 5 and index 10 is at index {1}.", myString, myIndex );
}

void PrintIndexAndValues( Array^ myArray )
{
   for ( int i = myArray->GetLowerBound( 0 ); i <= myArray->GetUpperBound( 0 ); i++ )
      Console::WriteLine(  "\t[{0}]:\t{1}", i, myArray->GetValue( i ) );
}

/* 
 This code produces the following output.
 
 The Array instance contains the following values:
     [0]:    the
     [1]:    quick
     [2]:    brown
     [3]:    fox
     [4]:    jumps
     [5]:    over
     [6]:    the
     [7]:    lazy
     [8]:    dog
     [9]:    in
     [10]:    the
     [11]:    barn
 The last occurrence of "the" is at index 10.
 The last occurrence of "the" between the start and index 8 is at index 6.
 The last occurrence of "the" between index 5 and index 10 is at index 10.
 */
// Creates and initializes a new Array with three elements of the same value.
Array myArray=Array.CreateInstance( typeof(String), 12 );
myArray.SetValue( "the", 0 );
myArray.SetValue( "quick", 1 );
myArray.SetValue( "brown", 2 );
myArray.SetValue( "fox", 3 );
myArray.SetValue( "jumps", 4 );
myArray.SetValue( "over", 5 );
myArray.SetValue( "the", 6 );
myArray.SetValue( "lazy", 7 );
myArray.SetValue( "dog", 8 );
myArray.SetValue( "in", 9 );
myArray.SetValue( "the", 10 );
myArray.SetValue( "barn", 11 );

// Displays the values of the Array.
Console.WriteLine( "The Array contains the following values:" );
PrintIndexAndValues( myArray );

// Searches for the last occurrence of the duplicated value.
String myString = "the";
int myIndex = Array.LastIndexOf( myArray, myString );
Console.WriteLine( "The last occurrence of \"{0}\" is at index {1}.", myString, myIndex );

// Searches for the last occurrence of the duplicated value in the first section of the Array.
myIndex = Array.LastIndexOf( myArray, myString, 8 );
Console.WriteLine( "The last occurrence of \"{0}\" between the start and index 8 is at index {1}.", myString, myIndex );

// Searches for the last occurrence of the duplicated value in a section of the Array.
// Note that the start index is greater than the end index because the search is done backward.
myIndex = Array.LastIndexOf( myArray, myString, 10, 6 );
Console.WriteLine( "The last occurrence of \"{0}\" between index 5 and index 10 is at index {1}.", myString, myIndex );

void PrintIndexAndValues( Array anArray )  {
   for ( int i = anArray.GetLowerBound(0); i <= anArray.GetUpperBound(0); i++ )
      Console.WriteLine( "\t[{0}]:\t{1}", i, anArray.GetValue( i ) );
}

/*
This code produces the following output.

The Array contains the following values:
   [0]:    the
   [1]:    quick
   [2]:    brown
   [3]:    fox
   [4]:    jumps
   [5]:    over
   [6]:    the
   [7]:    lazy
   [8]:    dog
   [9]:    in
   [10]:    the
   [11]:    barn
The last occurrence of "the" is at index 10.
The last occurrence of "the" between the start and index 8 is at index 6.
The last occurrence of "the" between index 5 and index 10 is at index 10.
*/
Public Class SamplesArray    
    
    Public Shared Sub Main()
        
        ' Creates and initializes a new Array with three elements of
        ' the same value.
        Dim myArray As Array = Array.CreateInstance(GetType(String), 12)
        myArray.SetValue("the", 0)
        myArray.SetValue("quick", 1)
        myArray.SetValue("brown", 2)
        myArray.SetValue("fox", 3)
        myArray.SetValue("jumps", 4)
        myArray.SetValue("over", 5)
        myArray.SetValue("the", 6)
        myArray.SetValue("lazy", 7)
        myArray.SetValue("dog", 8)
        myArray.SetValue("in", 9)
        myArray.SetValue("the", 10)
        myArray.SetValue("barn", 11)
        
        ' Displays the values of the Array.
        Console.WriteLine("The Array contains the following values:")
        PrintIndexAndValues(myArray)
        
        ' Searches for the last occurrence of the duplicated value.
        Dim myString As String = "the"
        Dim myIndex As Integer = Array.LastIndexOf(myArray, myString)
        Console.WriteLine("The last occurrence of ""{0}"" is at index {1}.", _
           myString, myIndex)
        
        ' Searches for the last occurrence of the duplicated value in the first
        ' section of the Array.
        myIndex = Array.LastIndexOf(myArray, myString, 8)
        Console.WriteLine("The last occurrence of ""{0}"" between the start " _
           + "and index 8 is at index {1}.", myString, myIndex)
        
        ' Searches for the last occurrence of the duplicated value in a section
        ' of the Array.  Note that the start index is greater than the end
        ' index because the search is done backward.
        myIndex = Array.LastIndexOf(myArray, myString, 10, 6)
        Console.WriteLine("The last occurrence of ""{0}"" between index 5 " _
           + "and index 10 is at index {1}.", myString, myIndex)
    End Sub
    
    
    Public Shared Sub PrintIndexAndValues(myArray As Array)
        Dim i As Integer
        For i = myArray.GetLowerBound(0) To myArray.GetUpperBound(0)
            Console.WriteLine(ControlChars.Tab + "[{0}]:" + ControlChars.Tab _
               + "{1}", i, myArray.GetValue(i))
        Next i
    End Sub
End Class

' This code produces the following output.
' 
' The Array contains the following values:
'     [0]:    the
'     [1]:    quick
'     [2]:    brown
'     [3]:    fox
'     [4]:    jumps
'     [5]:    over
'     [6]:    the
'     [7]:    lazy
'     [8]:    dog
'     [9]:    in
'     [10]:    the
'     [11]:    barn
' The last occurrence of "the" is at index 10.
' The last occurrence of "the" between the start and index 8 is at index 6.
' The last occurrence of "the" between index 5 and index 10 is at index 10. 

Remarks

一維 Array 會從 startIndex 開始向前搜尋,並在 startIndexcount 加1(如果 count 大於0)結束。The one-dimensional Array is searched backward starting at startIndex and ending at startIndex minus count plus 1, if count is greater than 0.

使用 Object.Equals 方法,將元素與指定的值進行比較。The elements are compared to the specified value using the Object.Equals method. 如果元素類型是 nonintrinsic (使用者定義的)類型,則會使用該類型的Equals 實作為。If the element type is a nonintrinsic (user-defined) type, theEquals implementation of that type is used.

因為大部分陣列的下限都是零,所以當找不到 value 時,這個方法通常會傳回-1。Since most arrays will have a lower bound of zero, this method would generally return -1 when value is not found. 在陣列下限等於 Int32.MinValue 且找不到 value 的罕見情況下,這個方法會傳回 Int32.MaxValue,這是 System.Int32.MinValue - 1In the rare case that the lower bound of the array is equal to Int32.MinValue and value is not found, this method returns Int32.MaxValue, which is System.Int32.MinValue - 1.

這個方法是 O (n)運算,其中 ncountThis method is an O(n) operation, where n is count.

在 .NET Framework 版本2.0 中,這個方法會使用 ArrayEqualsCompareTo 方法,來判斷 Object 參數所指定的 value 是否存在。In the .NET Framework version 2.0, this method uses the Equals and CompareTo methods of the Array to determine whether the Object specified by the value parameter exists. 在舊版的 .NET Framework 中,這項決定是使用 valueObject 本身的 EqualsCompareTo 方法進行。In the earlier versions of the .NET Framework, this determination was made by using the Equals and CompareTo methods of the valueObject itself.

See also

LastIndexOf<T>(T[], T)

搜尋指定的物件,並傳回整個 Array 中最後一個相符項目的索引。Searches for the specified object and returns the index of the last occurrence within the entire Array.

public:
generic <typename T>
 static int LastIndexOf(cli::array <T> ^ array, T value);
public static int LastIndexOf<T> (T[] array, T value);
static member LastIndexOf : 'T[] * 'T -> int
Public Shared Function LastIndexOf(Of T) (array As T(), value As T) As Integer

Type Parameters

T

陣列項目的類型。The type of the elements of the array.

Parameters

array
T[]

要搜尋的以零為起始的一維 ArrayThe one-dimensional, zero-based Array to search.

value
T

要在 array 中尋找的物件。The object to locate in array.

Returns

Int32

整個 array 中最後一次出現 value 之以零為起始的索引;如未找到則為 -1。The zero-based index of the last occurrence of value within the entire array, if found; otherwise, -1.

Exceptions

arraynullarray is null.

Examples

下列程式碼範例會示範 LastIndexOf 方法的所有三個泛型多載。The following code example demonstrates all three generic overloads of the LastIndexOf method. 系統會建立一個字串陣列,其中有一個專案出現兩次,索引位置為0,索引位置為5。An array of strings is created, with one entry that appears twice, at index location 0 and index location 5. LastIndexOf<T>(T[], T) 方法多載會從結尾處搜尋整個陣列,並尋找第二個出現的字串。The LastIndexOf<T>(T[], T) method overload searches the entire array from the end, and finds the second occurrence of the string. LastIndexOf<T>(T[], T, Int32) 方法多載是用來從索引位置3開始向前搜尋陣列,並繼續到陣列的開頭,並尋找第一個出現的字串。The LastIndexOf<T>(T[], T, Int32) method overload is used to search the array backward beginning with index location 3 and continuing to the beginning of the array, and finds the first occurrence of the string. 最後,LastIndexOf<T>(T[], T, Int32, Int32) 方法多載是用來搜尋四個專案的範圍,從索引位置4開始並向後延伸(也就是,它會搜尋位於位置4、3、2和1的專案);此搜尋會傳回-1,因為該範圍內沒有搜尋字串的實例。Finally, the LastIndexOf<T>(T[], T, Int32, Int32) method overload is used to search a range of four entries, beginning at index location 4 and extending backward (that is, it searches the items at locations 4, 3, 2, and 1); this search returns -1 because there are no instances of the search string in that range.

using namespace System;

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

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

    Console::WriteLine(
        "\nArray.LastIndexOf(dinosaurs, \"Tyrannosaurus\"): {0}", 
        Array::LastIndexOf(dinosaurs, "Tyrannosaurus"));

    Console::WriteLine(
        "\nArray.LastIndexOf(dinosaurs, \"Tyrannosaurus\", 3): {0}", 
        Array::LastIndexOf(dinosaurs, "Tyrannosaurus", 3));

    Console::WriteLine(
        "\nArray.LastIndexOf(dinosaurs, \"Tyrannosaurus\", 4, 4): {0}", 
        Array::LastIndexOf(dinosaurs, "Tyrannosaurus", 4, 4));
}

/* This code example produces the following output:

Tyrannosaurus
Amargasaurus
Mamenchisaurus
Brachiosaurus
Deinonychus
Tyrannosaurus
Compsognathus

Array.LastIndexOf(dinosaurs, "Tyrannosaurus"): 5

Array.LastIndexOf(dinosaurs, "Tyrannosaurus", 3): 0

Array.LastIndexOf(dinosaurs, "Tyrannosaurus", 4, 4): -1
 */
string[] dinosaurs = { "Tyrannosaurus",
    "Amargasaurus",
    "Mamenchisaurus",
    "Brachiosaurus",
    "Deinonychus",
    "Tyrannosaurus",
    "Compsognathus" };

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

Console.WriteLine(
    "\nArray.LastIndexOf(dinosaurs, \"Tyrannosaurus\"): {0}",
    Array.LastIndexOf(dinosaurs, "Tyrannosaurus"));

Console.WriteLine(
    "\nArray.LastIndexOf(dinosaurs, \"Tyrannosaurus\", 3): {0}",
    Array.LastIndexOf(dinosaurs, "Tyrannosaurus", 3));

Console.WriteLine(
    "\nArray.LastIndexOf(dinosaurs, \"Tyrannosaurus\", 4, 4): {0}",
    Array.LastIndexOf(dinosaurs, "Tyrannosaurus", 4, 4));

/* This code example produces the following output:

Tyrannosaurus
Amargasaurus
Mamenchisaurus
Brachiosaurus
Deinonychus
Tyrannosaurus
Compsognathus

Array.LastIndexOf(dinosaurs, "Tyrannosaurus"): 5

Array.LastIndexOf(dinosaurs, "Tyrannosaurus", 3): 0

Array.LastIndexOf(dinosaurs, "Tyrannosaurus", 4, 4): -1
*/
Public Class Example

    Public Shared Sub Main()

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

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

        Console.WriteLine(vbLf & _
            "Array.LastIndexOf(dinosaurs, ""Tyrannosaurus""): {0}", _
            Array.LastIndexOf(dinosaurs, "Tyrannosaurus"))

        Console.WriteLine(vbLf & _
            "Array.LastIndexOf(dinosaurs, ""Tyrannosaurus"", 3): {0}", _
            Array.LastIndexOf(dinosaurs, "Tyrannosaurus", 3))

        Console.WriteLine(vbLf & _
            "Array.LastIndexOf(dinosaurs, ""Tyrannosaurus"", 4, 4): {0}", _
            Array.LastIndexOf(dinosaurs, "Tyrannosaurus", 4, 4))

    End Sub
End Class

' This code example produces the following output:
'
'Tyrannosaurus
'Amargasaurus
'Mamenchisaurus
'Brachiosaurus
'Deinonychus
'Tyrannosaurus
'Compsognathus
'
'Array.LastIndexOf(dinosaurs, "Tyrannosaurus"): 5
'
'Array.LastIndexOf(dinosaurs, "Tyrannosaurus", 3): 0
'
'Array.LastIndexOf(dinosaurs, "Tyrannosaurus", 4, 4): -1

Remarks

Array 會從最後一個專案開始向前搜尋,並在第一個元素結束。The Array is searched backward starting at the last element and ending at the first element.

使用 Object.Equals 方法,將元素與指定的值進行比較。The elements are compared to the specified value using the Object.Equals method. 如果元素類型是 nonintrinsic (使用者定義的)類型,則會使用該類型的 Equals 實作為。If the element type is a nonintrinsic (user-defined) type, the Equals implementation of that type is used.

這個方法是 O (n)運算,其中 narrayLengthThis method is an O(n) operation, where n is the Length of array.

See also

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

Array 中從第一個項目開始到指定的索引這段範圍的項目內,搜尋指定的物件最後一次出現的位置,並傳回其索引值 (索引以零為起始)。Searches for the specified object and returns the index of the last occurrence within the range of elements in the Array that extends from the first element to the specified index.

public:
generic <typename T>
 static int LastIndexOf(cli::array <T> ^ array, T value, int startIndex);
public static int LastIndexOf<T> (T[] array, T value, int startIndex);
static member LastIndexOf : 'T[] * 'T * int -> int
Public Shared Function LastIndexOf(Of T) (array As T(), value As T, startIndex As Integer) As Integer

Type Parameters

T

陣列項目的類型。The type of the elements of the array.

Parameters

array
T[]

要搜尋的以零為起始的一維 ArrayThe one-dimensional, zero-based Array to search.

value
T

要在 array 中尋找的物件。The object to locate in array.

startIndex
Int32

向後搜尋之以零為起始的起始索引。The zero-based starting index of the backward search.

Returns

Int32

array 中從第一個項目到 startIndex 的項目範圍內,最後一次出現 value 之以零為起始的索引;如未找到則為 -1。The zero-based index of the last occurrence of value within the range of elements in array that extends from the first element to startIndex, if found; otherwise, -1.

Exceptions

arraynullarray is null.

startIndex 超出 array 的有效索引範圍。startIndex is outside the range of valid indexes for array.

Examples

下列程式碼範例會示範 LastIndexOf 方法的所有三個泛型多載。The following code example demonstrates all three generic overloads of the LastIndexOf method. 系統會建立一個字串陣列,其中有一個專案出現兩次,索引位置為0,索引位置為5。An array of strings is created, with one entry that appears twice, at index location 0 and index location 5. LastIndexOf<T>(T[], T) 方法多載會從結尾處搜尋整個陣列,並尋找第二個出現的字串。The LastIndexOf<T>(T[], T) method overload searches the entire array from the end, and finds the second occurrence of the string. LastIndexOf<T>(T[], T, Int32) 方法多載是用來從索引位置3開始向前搜尋陣列,並繼續到陣列的開頭,並尋找第一個出現的字串。The LastIndexOf<T>(T[], T, Int32) method overload is used to search the array backward beginning with index location 3 and continuing to the beginning of the array, and finds the first occurrence of the string. 最後,LastIndexOf<T>(T[], T, Int32, Int32) 方法多載是用來搜尋四個專案的範圍,從索引位置4開始並向後延伸(也就是,它會搜尋位於位置4、3、2和1的專案);此搜尋會傳回-1,因為該範圍內沒有搜尋字串的實例。Finally, the LastIndexOf<T>(T[], T, Int32, Int32) method overload is used to search a range of four entries, beginning at index location 4 and extending backward (that is, it searches the items at locations 4, 3, 2, and 1); this search returns -1 because there are no instances of the search string in that range.

using namespace System;

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

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

    Console::WriteLine(
        "\nArray.LastIndexOf(dinosaurs, \"Tyrannosaurus\"): {0}", 
        Array::LastIndexOf(dinosaurs, "Tyrannosaurus"));

    Console::WriteLine(
        "\nArray.LastIndexOf(dinosaurs, \"Tyrannosaurus\", 3): {0}", 
        Array::LastIndexOf(dinosaurs, "Tyrannosaurus", 3));

    Console::WriteLine(
        "\nArray.LastIndexOf(dinosaurs, \"Tyrannosaurus\", 4, 4): {0}", 
        Array::LastIndexOf(dinosaurs, "Tyrannosaurus", 4, 4));
}

/* This code example produces the following output:

Tyrannosaurus
Amargasaurus
Mamenchisaurus
Brachiosaurus
Deinonychus
Tyrannosaurus
Compsognathus

Array.LastIndexOf(dinosaurs, "Tyrannosaurus"): 5

Array.LastIndexOf(dinosaurs, "Tyrannosaurus", 3): 0

Array.LastIndexOf(dinosaurs, "Tyrannosaurus", 4, 4): -1
 */
string[] dinosaurs = { "Tyrannosaurus",
    "Amargasaurus",
    "Mamenchisaurus",
    "Brachiosaurus",
    "Deinonychus",
    "Tyrannosaurus",
    "Compsognathus" };

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

Console.WriteLine(
    "\nArray.LastIndexOf(dinosaurs, \"Tyrannosaurus\"): {0}",
    Array.LastIndexOf(dinosaurs, "Tyrannosaurus"));

Console.WriteLine(
    "\nArray.LastIndexOf(dinosaurs, \"Tyrannosaurus\", 3): {0}",
    Array.LastIndexOf(dinosaurs, "Tyrannosaurus", 3));

Console.WriteLine(
    "\nArray.LastIndexOf(dinosaurs, \"Tyrannosaurus\", 4, 4): {0}",
    Array.LastIndexOf(dinosaurs, "Tyrannosaurus", 4, 4));

/* This code example produces the following output:

Tyrannosaurus
Amargasaurus
Mamenchisaurus
Brachiosaurus
Deinonychus
Tyrannosaurus
Compsognathus

Array.LastIndexOf(dinosaurs, "Tyrannosaurus"): 5

Array.LastIndexOf(dinosaurs, "Tyrannosaurus", 3): 0

Array.LastIndexOf(dinosaurs, "Tyrannosaurus", 4, 4): -1
*/
Public Class Example

    Public Shared Sub Main()

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

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

        Console.WriteLine(vbLf & _
            "Array.LastIndexOf(dinosaurs, ""Tyrannosaurus""): {0}", _
            Array.LastIndexOf(dinosaurs, "Tyrannosaurus"))

        Console.WriteLine(vbLf & _
            "Array.LastIndexOf(dinosaurs, ""Tyrannosaurus"", 3): {0}", _
            Array.LastIndexOf(dinosaurs, "Tyrannosaurus", 3))

        Console.WriteLine(vbLf & _
            "Array.LastIndexOf(dinosaurs, ""Tyrannosaurus"", 4, 4): {0}", _
            Array.LastIndexOf(dinosaurs, "Tyrannosaurus", 4, 4))

    End Sub
End Class

' This code example produces the following output:
'
'Tyrannosaurus
'Amargasaurus
'Mamenchisaurus
'Brachiosaurus
'Deinonychus
'Tyrannosaurus
'Compsognathus
'
'Array.LastIndexOf(dinosaurs, "Tyrannosaurus"): 5
'
'Array.LastIndexOf(dinosaurs, "Tyrannosaurus", 3): 0
'
'Array.LastIndexOf(dinosaurs, "Tyrannosaurus", 4, 4): -1

Remarks

Array 會從 startIndex 開始向前搜尋,並在第一個元素結束。The Array is searched backward starting at startIndex and ending at the first element.

使用 Object.Equals 方法,將元素與指定的值進行比較。The elements are compared to the specified value using the Object.Equals method. 如果元素類型是 nonintrinsic (使用者定義的)類型,則會使用該類型的 Equals 實作為。If the element type is a nonintrinsic (user-defined) type, the Equals implementation of that type is used.

這個方法是 O (n)運算,其中 n 是從 array 開頭到 startIndex的元素數目。This method is an O(n) operation, where n is the number of elements from the beginning of array to startIndex.

See also

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

搜尋指定的物件,並傳回 Array 中包含指定之項目數且結束於指定之索引的項目範圍內,最後一個相符項目的索引。Searches for the specified object and returns the index of the last occurrence within the range of elements in the Array that contains the specified number of elements and ends at the specified index.

public:
generic <typename T>
 static int LastIndexOf(cli::array <T> ^ array, T value, int startIndex, int count);
public static int LastIndexOf<T> (T[] array, T value, int startIndex, int count);
static member LastIndexOf : 'T[] * 'T * int * int -> int
Public Shared Function LastIndexOf(Of T) (array As T(), value As T, startIndex As Integer, count As Integer) As Integer

Type Parameters

T

陣列項目的類型。The type of the elements of the array.

Parameters

array
T[]

要搜尋的以零為起始的一維 ArrayThe one-dimensional, zero-based Array to search.

value
T

要在 array 中尋找的物件。The object to locate in array.

startIndex
Int32

向後搜尋之以零為起始的起始索引。The zero-based starting index of the backward search.

count
Int32

區段中要搜尋的項目數目。The number of elements in the section to search.

Returns

Int32

array 中包含 count 中指定項目數且結束於 startIndex 的項目範圍內,最後一次出現 value 之以零為起始的索引;如未找到則為 -1。The zero-based index of the last occurrence of value within the range of elements in array that contains the number of elements specified in count and ends at startIndex, if found; otherwise, -1.

Exceptions

arraynullarray is null.

startIndex 超出 array 的有效索引範圍。startIndex is outside the range of valid indexes for array.

-或--or- count 小於零。count is less than zero.

-或--or- startIndexcount 不指定 array 的有效區段。startIndex and count do not specify a valid section in array.

Examples

下列程式碼範例會示範 LastIndexOf 方法的所有三個泛型多載。The following code example demonstrates all three generic overloads of the LastIndexOf method. 系統會建立一個字串陣列,其中有一個專案出現兩次,索引位置為0,索引位置為5。An array of strings is created, with one entry that appears twice, at index location 0 and index location 5. LastIndexOf<T>(T[], T) 方法多載會從結尾處搜尋整個陣列,並尋找第二個出現的字串。The LastIndexOf<T>(T[], T) method overload searches the entire array from the end, and finds the second occurrence of the string. LastIndexOf<T>(T[], T, Int32) 方法多載是用來從索引位置3開始向前搜尋陣列,並繼續到陣列的開頭,並尋找第一個出現的字串。The LastIndexOf<T>(T[], T, Int32) method overload is used to search the array backward beginning with index location 3 and continuing to the beginning of the array, and finds the first occurrence of the string. 最後,LastIndexOf<T>(T[], T, Int32, Int32) 方法多載是用來搜尋四個專案的範圍,從索引位置4開始並向後延伸(也就是,它會搜尋位於位置4、3、2和1的專案);此搜尋會傳回-1,因為該範圍內沒有搜尋字串的實例。Finally, the LastIndexOf<T>(T[], T, Int32, Int32) method overload is used to search a range of four entries, beginning at index location 4 and extending backward (that is, it searches the items at locations 4, 3, 2, and 1); this search returns -1 because there are no instances of the search string in that range.

using namespace System;

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

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

    Console::WriteLine(
        "\nArray.LastIndexOf(dinosaurs, \"Tyrannosaurus\"): {0}", 
        Array::LastIndexOf(dinosaurs, "Tyrannosaurus"));

    Console::WriteLine(
        "\nArray.LastIndexOf(dinosaurs, \"Tyrannosaurus\", 3): {0}", 
        Array::LastIndexOf(dinosaurs, "Tyrannosaurus", 3));

    Console::WriteLine(
        "\nArray.LastIndexOf(dinosaurs, \"Tyrannosaurus\", 4, 4): {0}", 
        Array::LastIndexOf(dinosaurs, "Tyrannosaurus", 4, 4));
}

/* This code example produces the following output:

Tyrannosaurus
Amargasaurus
Mamenchisaurus
Brachiosaurus
Deinonychus
Tyrannosaurus
Compsognathus

Array.LastIndexOf(dinosaurs, "Tyrannosaurus"): 5

Array.LastIndexOf(dinosaurs, "Tyrannosaurus", 3): 0

Array.LastIndexOf(dinosaurs, "Tyrannosaurus", 4, 4): -1
 */
string[] dinosaurs = { "Tyrannosaurus",
    "Amargasaurus",
    "Mamenchisaurus",
    "Brachiosaurus",
    "Deinonychus",
    "Tyrannosaurus",
    "Compsognathus" };

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

Console.WriteLine(
    "\nArray.LastIndexOf(dinosaurs, \"Tyrannosaurus\"): {0}",
    Array.LastIndexOf(dinosaurs, "Tyrannosaurus"));

Console.WriteLine(
    "\nArray.LastIndexOf(dinosaurs, \"Tyrannosaurus\", 3): {0}",
    Array.LastIndexOf(dinosaurs, "Tyrannosaurus", 3));

Console.WriteLine(
    "\nArray.LastIndexOf(dinosaurs, \"Tyrannosaurus\", 4, 4): {0}",
    Array.LastIndexOf(dinosaurs, "Tyrannosaurus", 4, 4));

/* This code example produces the following output:

Tyrannosaurus
Amargasaurus
Mamenchisaurus
Brachiosaurus
Deinonychus
Tyrannosaurus
Compsognathus

Array.LastIndexOf(dinosaurs, "Tyrannosaurus"): 5

Array.LastIndexOf(dinosaurs, "Tyrannosaurus", 3): 0

Array.LastIndexOf(dinosaurs, "Tyrannosaurus", 4, 4): -1
*/
Public Class Example

    Public Shared Sub Main()

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

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

        Console.WriteLine(vbLf & _
            "Array.LastIndexOf(dinosaurs, ""Tyrannosaurus""): {0}", _
            Array.LastIndexOf(dinosaurs, "Tyrannosaurus"))

        Console.WriteLine(vbLf & _
            "Array.LastIndexOf(dinosaurs, ""Tyrannosaurus"", 3): {0}", _
            Array.LastIndexOf(dinosaurs, "Tyrannosaurus", 3))

        Console.WriteLine(vbLf & _
            "Array.LastIndexOf(dinosaurs, ""Tyrannosaurus"", 4, 4): {0}", _
            Array.LastIndexOf(dinosaurs, "Tyrannosaurus", 4, 4))

    End Sub
End Class

' This code example produces the following output:
'
'Tyrannosaurus
'Amargasaurus
'Mamenchisaurus
'Brachiosaurus
'Deinonychus
'Tyrannosaurus
'Compsognathus
'
'Array.LastIndexOf(dinosaurs, "Tyrannosaurus"): 5
'
'Array.LastIndexOf(dinosaurs, "Tyrannosaurus", 3): 0
'
'Array.LastIndexOf(dinosaurs, "Tyrannosaurus", 4, 4): -1

Remarks

Array 會從 startIndex 開始向前搜尋,並在 startIndexcount 加1(如果 count 大於0)結束。The Array is searched backward starting at startIndex and ending at startIndex minus count plus 1, if count is greater than 0.

使用 Object.Equals 方法,將元素與指定的值進行比較。The elements are compared to the specified value using the Object.Equals method. 如果元素類型是 nonintrinsic (使用者定義的)類型,則會使用該類型的 Equals 實作為。If the element type is a nonintrinsic (user-defined) type, the Equals implementation of that type is used.

這個方法是 O (n)運算,其中 ncountThis method is an O(n) operation, where n is count.

See also

Applies to