Array.LastIndexOf 方法

参考

定义

命名空间:: System

程序集:: System.Runtime.dll

程序集:: mscorlib.dll

程序集:: netstandard.dll

重要

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返回一维 Array 或 Array部分的值的最后一个匹配项的索引。

重载

LastIndexOf(Array, Object)	搜索指定的对象，并返回整个一维 Array中最后一个匹配项的索引。
LastIndexOf(Array, Object, Int32)	搜索指定的对象，并返回从第一个元素扩展到指定索引的一维 Array 中最后一个匹配项的索引。
LastIndexOf(Array, Object, Int32, Int32)	搜索指定的对象，并返回一维 Array 中包含指定数量的元素并在指定索引处结束的元素范围内最后一个匹配项的索引。
LastIndexOf<T>(T[], T)	搜索指定的对象并返回整个 Array中最后一个匹配项的索引。
LastIndexOf<T>(T[], T, Int32)	搜索指定的对象，并返回从第一个元素扩展到指定索引的 Array 中最后一个匹配项的索引。
LastIndexOf<T>(T[], T, Int32, Int32)	搜索指定的对象，并返回 Array 中包含指定数量的元素并在指定索引处结束的元素范围内的最后一个匹配项的索引。

LastIndexOf(Array, Object)

Source:: Array.cs

Source:: Array.cs

Source:: Array.cs

搜索指定的对象，并返回整个一维 Array中最后一个匹配项的索引。

public:
 static int LastIndexOf(Array ^ array, System::Object ^ value);

public static int LastIndexOf (Array array, 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

参数

array: Array

要搜索的一维 Array。

value: Object

在 array中查找的对象。

Int32

如果找到，则整个 array中最后 value 匹配项的索引;否则，数组的下限减 1。

例外

ArgumentNullException

array null。

RankException

array 是多维的。

示例

下面的代码示例演示如何确定数组中指定元素的最后一个匹配项的索引。

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.
 */

let printIndexAndValues (arr: 'a []) =
   for i = arr.GetLowerBound 0 to arr.GetUpperBound 0 do
      printfn $"\t[{i}]:\t{arr[i]}"

// Creates and initializes a new Array with three elements of the same value.
let myArray = 
   [| "the"; "quick"; "brown"; "fox"
      "jumps"; "over"; "the"; "lazy"
      "dog"; "in"; "the"; "barn" |]

// Displays the values of the Array.
printfn "The Array contains the following values:"
printIndexAndValues myArray

// Searches for the last occurrence of the duplicated value.
let myString = "the"
let myIndex = Array.LastIndexOf(myArray, myString)
printfn $"The last occurrence of \"{myString}\" is at index {myIndex}."

// Searches for the last occurrence of the duplicated value in the first section of the Array.
let myIndex = Array.LastIndexOf(myArray, myString, 8)
printfn $"The last occurrence of \"{myString}\" between the start and index 8 is at index {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.
let myIndex = Array.LastIndexOf( myArray, myString, 10, 6 )
printfn $"The last occurrence of \"{myString}\" between index 5 and index 10 is at index {myIndex}."


//      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.

// 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.

注解

一维 Array 从最后一个元素开始向后搜索，最后一个元素结束。

使用 Object.Equals 方法将元素与指定值进行比较。如果元素类型是非内联类型（用户定义的）类型，则使用该类型的 Equals 实现。

由于大多数数组的下限为零，因此在找不到 value 时，此方法通常会返回 -1。在极少数情况下，数组的下限等于 Int32.MinValue，找不到 value，此方法返回 Int32.MaxValue，即 System.Int32.MinValue - 1。

此方法是 O（n）操作，其中 n 是 array的 Length。

在 .NET Framework 2.0 及更高版本中，此方法使用 Array Equals 和 CompareTo 方法来确定 value 参数指定的 Object 是否存在。在早期版本的 .NET Framework 中，使用 valueObject 本身的 Equals 和 CompareTo 方法做出了此决定。

CompareTo 集合中对象的 item 参数的方法。

另请参阅

IndexOf
在数组中执行 Culture-Insensitive 字符串操作

适用于

LastIndexOf(Array, Object, Int32)

Source:: Array.cs

Source:: Array.cs

Source:: Array.cs

搜索指定的对象，并返回从第一个元素扩展到指定索引的一维 Array 中最后一个匹配项的索引。

public:
 static int LastIndexOf(Array ^ array, System::Object ^ value, int startIndex);

public static int LastIndexOf (Array array, 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

参数

array: Array

要搜索的一维 Array。

value: Object

在 array中查找的对象。

startIndex: Int32

向后搜索的起始索引。

Int32

在从第一个元素扩展到 startIndex的 array 元素范围内最后 value 的索引（如果找到）;否则，数组的下限减 1。

例外

ArgumentNullException

array null。

ArgumentOutOfRangeException

startIndex 超出了 array的有效索引范围。

RankException

array 是多维的。

示例

下面的代码示例演示如何确定数组中指定元素的最后一个匹配项的索引。

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.
 */

let printIndexAndValues (arr: 'a []) =
   for i = arr.GetLowerBound 0 to arr.GetUpperBound 0 do
      printfn $"\t[{i}]:\t{arr[i]}"

// Creates and initializes a new Array with three elements of the same value.
let myArray = 
   [| "the"; "quick"; "brown"; "fox"
      "jumps"; "over"; "the"; "lazy"
      "dog"; "in"; "the"; "barn" |]

// Displays the values of the Array.
printfn "The Array contains the following values:"
printIndexAndValues myArray

// Searches for the last occurrence of the duplicated value.
let myString = "the"
let myIndex = Array.LastIndexOf(myArray, myString)
printfn $"The last occurrence of \"{myString}\" is at index {myIndex}."

// Searches for the last occurrence of the duplicated value in the first section of the Array.
let myIndex = Array.LastIndexOf(myArray, myString, 8)
printfn $"The last occurrence of \"{myString}\" between the start and index 8 is at index {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.
let myIndex = Array.LastIndexOf( myArray, myString, 10, 6 )
printfn $"The last occurrence of \"{myString}\" between index 5 and index 10 is at index {myIndex}."


//      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.

// 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.

注解

一维 Array 从 startIndex 开始向后搜索，并在第一个元素处结束。

使用 Object.Equals 方法将元素与指定值进行比较。如果元素类型是非内联类型（用户定义的）类型，则使用该类型的 Equals 实现。

此方法是 O（n）操作，其中 n 是从 array 开始到 startIndex的元素数。

另请参阅

IndexOf
在数组中执行 Culture-Insensitive 字符串操作

适用于

LastIndexOf(Array, Object, Int32, Int32)

Source:: Array.cs

Source:: Array.cs

Source:: Array.cs

搜索指定的对象，并返回一维 Array 中包含指定数量的元素并在指定索引处结束的元素范围内最后一个匹配项的索引。

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);

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

参数

array: Array

要搜索的一维 Array。

value: Object

在 array中查找的对象。

startIndex: Int32

向后搜索的起始索引。

count: Int32

要搜索的节中的元素数。

Int32

array 中 value 最后一个匹配项的索引，其中包含在 count 中指定的元素数，并在 startIndex处结束（如果找到）;否则，数组的下限减 1。

例外

ArgumentNullException

array null。

ArgumentOutOfRangeException

startIndex 超出了 array的有效索引范围。

-或-

count 小于零。

-或-

startIndex 和 count 未在 array中指定有效的节。

RankException

array 是多维的。

示例

下面的代码示例演示如何确定数组中指定元素的最后一个匹配项的索引。请注意，LastIndexOf 方法是向后搜索;因此，count 必须小于或等于（startIndex 减去数组的下限加 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.
 */

let printIndexAndValues (arr: 'a []) =
   for i = arr.GetLowerBound 0 to arr.GetUpperBound 0 do
      printfn $"\t[{i}]:\t{arr[i]}"

// Creates and initializes a new Array with three elements of the same value.
let myArray = 
   [| "the"; "quick"; "brown"; "fox"
      "jumps"; "over"; "the"; "lazy"
      "dog"; "in"; "the"; "barn" |]

// Displays the values of the Array.
printfn "The Array contains the following values:"
printIndexAndValues myArray

// Searches for the last occurrence of the duplicated value.
let myString = "the"
let myIndex = Array.LastIndexOf(myArray, myString)
printfn $"The last occurrence of \"{myString}\" is at index {myIndex}."

// Searches for the last occurrence of the duplicated value in the first section of the Array.
let myIndex = Array.LastIndexOf(myArray, myString, 8)
printfn $"The last occurrence of \"{myString}\" between the start and index 8 is at index {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.
let myIndex = Array.LastIndexOf( myArray, myString, 10, 6 )
printfn $"The last occurrence of \"{myString}\" between index 5 and index 10 is at index {myIndex}."


//      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.

// 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.

注解

一维 Array 从 startIndex 开始向后搜索，如果 count 大于 0，则从 startIndex 减 count 加 1 结束。

使用 Object.Equals 方法将元素与指定值进行比较。如果元素类型是非三一类型（用户定义的）类型，则使用该类型的Equals 实现。

此方法是一个 O（n）操作，其中 ncount。

另请参阅

IndexOf
在数组中执行 Culture-Insensitive 字符串操作

适用于

LastIndexOf<T>(T[], T)

Source:: Array.cs

Source:: Array.cs

Source:: Array.cs

搜索指定的对象并返回整个 Array中最后一个匹配项的索引。

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

类型参数

T

数组元素的类型。

参数

array: T[]

要搜索的从零开始的一维 Array。

value: T

在 array中查找的对象。

Int32

如果找到，则为整个 array中最后 value 的从零开始的索引;否则为 -1。

例外

ArgumentNullException

array null。

示例

下面的代码示例演示 LastIndexOf 方法的所有三个泛型重载。创建字符串数组，其中一个条目出现在索引位置 0 和索引位置 5 处两次。 LastIndexOf<T>(T[], T) 方法重载从末尾搜索整个数组，并查找字符串的第二个匹配项。 LastIndexOf<T>(T[], T, Int32) 方法重载用于从索引位置 3 开始向后搜索数组，并继续到数组的开头，并查找字符串的第一个匹配项。最后，LastIndexOf<T>(T[], T, Int32, Int32) 方法重载用于搜索一系列四个条目，从索引位置 4 开始，向后扩展（也就是说，它会在位置 4、3、2 和 1 处搜索项）：此搜索返回 -1，因为该区域中没有搜索字符串的实例。

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
*/

open System

let dinosaurs = 
    [| "Tyrannosaurus"
       "Amargasaurus"
       "Mamenchisaurus"
       "Brachiosaurus"
       "Deinonychus"
       "Tyrannosaurus"
       "Compsognathus" |]

printfn ""
for dino in dinosaurs do
    printfn $"{dino}"

Array.LastIndexOf(dinosaurs, "Tyrannosaurus")
|> printfn "\nArray.LastIndexOf(dinosaurs, \"Tyrannosaurus\"): %i"

Array.LastIndexOf(dinosaurs, "Tyrannosaurus", 3)
|> printfn "\nArray.LastIndexOf(dinosaurs, \"Tyrannosaurus\", 3): %i"

Array.LastIndexOf(dinosaurs, "Tyrannosaurus", 4, 4)
|> printfn "\nArray.LastIndexOf(dinosaurs, \"Tyrannosaurus\", 4, 4): %i"

// 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

注解

从最后一个元素开始搜索 Array，最后一个元素结束。

使用 Object.Equals 方法将元素与指定值进行比较。如果元素类型是非内联类型（用户定义的）类型，则使用该类型的 Equals 实现。

此方法是 O（n）操作，其中 n 是 array的 Length。

另请参阅

IndexOf
在数组中执行 Culture-Insensitive 字符串操作

适用于

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

Source:: Array.cs

Source:: Array.cs

Source:: Array.cs

搜索指定的对象，并返回从第一个元素扩展到指定索引的 Array 中最后一个匹配项的索引。

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

类型参数

T

数组元素的类型。

参数

array: T[]

要搜索的从零开始的一维 Array。

value: T

在 array中查找的对象。

startIndex: Int32

从零开始的向后搜索索引。

Int32

在 array 中从第一个元素扩展到 startIndex的元素范围内 value 的从零开始的索引（如果找到）;否则为 -1。

例外

ArgumentNullException

array null。

ArgumentOutOfRangeException

startIndex 超出了 array的有效索引范围。

示例

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
*/

open System

let dinosaurs = 
    [| "Tyrannosaurus"
       "Amargasaurus"
       "Mamenchisaurus"
       "Brachiosaurus"
       "Deinonychus"
       "Tyrannosaurus"
       "Compsognathus" |]

printfn ""
for dino in dinosaurs do
    printfn $"{dino}"

Array.LastIndexOf(dinosaurs, "Tyrannosaurus")
|> printfn "\nArray.LastIndexOf(dinosaurs, \"Tyrannosaurus\"): %i"

Array.LastIndexOf(dinosaurs, "Tyrannosaurus", 3)
|> printfn "\nArray.LastIndexOf(dinosaurs, \"Tyrannosaurus\", 3): %i"

Array.LastIndexOf(dinosaurs, "Tyrannosaurus", 4, 4)
|> printfn "\nArray.LastIndexOf(dinosaurs, \"Tyrannosaurus\", 4, 4): %i"

// 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

注解

从 startIndex 开始搜索 Array，并在第一个元素处结束。

使用 Object.Equals 方法将元素与指定值进行比较。如果元素类型是非内联类型（用户定义的）类型，则使用该类型的 Equals 实现。

此方法是 O（n）操作，其中 n 是从 array 开始到 startIndex的元素数。

另请参阅

IndexOf
在数组中执行 Culture-Insensitive 字符串操作

适用于

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

Source:: Array.cs

Source:: Array.cs

Source:: Array.cs

搜索指定的对象，并返回 Array 中包含指定数量的元素并在指定索引处结束的元素范围内的最后一个匹配项的索引。

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

类型参数

T

数组元素的类型。

参数

array: T[]

要搜索的从零开始的一维 Array。

value: T

在 array中查找的对象。

startIndex: Int32

从零开始的向后搜索索引。

count: Int32

要搜索的节中的元素数。

Int32

array 中最后 value 匹配项的从零开始的索引，该索引包含 count 中指定的元素数，并在 startIndex处结束（如果找到）;否则为 -1。

例外

ArgumentNullException

array null。

ArgumentOutOfRangeException

startIndex 超出了 array的有效索引范围。

-或-

count 小于零。

-或-

startIndex 和 count 未在 array中指定有效的节。

示例

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
*/

open System

let dinosaurs = 
    [| "Tyrannosaurus"
       "Amargasaurus"
       "Mamenchisaurus"
       "Brachiosaurus"
       "Deinonychus"
       "Tyrannosaurus"
       "Compsognathus" |]

printfn ""
for dino in dinosaurs do
    printfn $"{dino}"

Array.LastIndexOf(dinosaurs, "Tyrannosaurus")
|> printfn "\nArray.LastIndexOf(dinosaurs, \"Tyrannosaurus\"): %i"

Array.LastIndexOf(dinosaurs, "Tyrannosaurus", 3)
|> printfn "\nArray.LastIndexOf(dinosaurs, \"Tyrannosaurus\", 3): %i"

Array.LastIndexOf(dinosaurs, "Tyrannosaurus", 4, 4)
|> printfn "\nArray.LastIndexOf(dinosaurs, \"Tyrannosaurus\", 4, 4): %i"

// 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

注解

如果 count 大于 0，则从 startIndex 开始搜索 Array，以减 count 加 1 startIndex 结尾。

使用 Object.Equals 方法将元素与指定值进行比较。如果元素类型是非内联类型（用户定义的）类型，则使用该类型的 Equals 实现。

此方法是一个 O（n）操作，其中 ncount。

另请参阅

IndexOf
在数组中执行 Culture-Insensitive 字符串操作

适用于

通过

Array.LastIndexOf 方法

定义

重载

LastIndexOf(Array, Object)

参数

返回

例外

示例

注解

另请参阅

适用于

LastIndexOf(Array, Object, Int32)

参数

返回

例外

示例

注解

另请参阅

适用于

LastIndexOf(Array, Object, Int32, Int32)

参数

返回

例外

示例

注解

另请参阅

适用于

LastIndexOf<T>(T[], T)

类型参数

参数

返回

例外

示例

注解

另请参阅

适用于

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

类型参数

参数

返回

例外

示例

注解

另请参阅

适用于

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

类型参数

参数

返回

例外

示例

注解

另请参阅

适用于

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