Array.IndexOf 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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在一个一维数组或该数组的一系列元素中搜索指定对象，并返回其首个匹配项的索引。

重载

IndexOf(Array, Object)	在一个一维数组中搜索指定对象，并返回其首个匹配项的索引。
IndexOf(Array, Object, Int32)	在一个一维数组的一系列元素中搜索指定对象，然后返回其首个匹配项的索引。范围从指定索引到该数组结尾。
IndexOf(Array, Object, Int32, Int32)	在一个一维数组的一系列元素中搜索指定对象，然后返回其首个匹配项的索引。该元素系列的范围从指定数量的元素的指定索引开始。
IndexOf<T>(T[], T, Int32)	在一个一维数组的一系列元素中搜索指定对象，然后返回其首个匹配项的索引。范围从指定索引到该数组结尾。
IndexOf<T>(T[], T, Int32, Int32)	在一个一维数组的一系列元素中搜索指定对象，然后返回其首个匹配项的索引。该元素系列的范围从指定数量的元素的指定索引开始。
IndexOf<T>(T[], T)	在一个一维数组中搜索指定对象，并返回其首个匹配项的索引。

IndexOf(Array, Object)

Source:: Array.cs

Source:: Array.cs

Source:: Array.cs

在一个一维数组中搜索指定对象，并返回其首个匹配项的索引。

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

public static int IndexOf (Array array, object value);

public static int IndexOf (Array array, object? value);

static member IndexOf : Array * obj -> int

Public Shared Function IndexOf (array As Array, value As Object) As Integer

参数

array: Array

要搜索的一维数组。

value: Object

要在 array 中查找的对象。

Int32

如果找到，则为 array 中 value 的第一个匹配项的索引；否则为该数组的下限减 1。

例外

ArgumentNullException

array 为 null。

RankException

array 是多维的。

示例

该示例调用方法的 IndexOf 以下三个重载，以查找字符串数组中字符串的索引：

IndexOf(Array, Object)，确定字符串数组中字符串“the”的第一个匹配项。
IndexOf(Array, Object, Int32)，用于确定字符串数组的第四个元素到最后一个元素中的字符串“the”的第一个匹配项。
IndexOf(Array, Object, Int32, Int32)，用于确定字符串数组中字符串“the”的第一个匹配项，该字符串从最后一个成功匹配项之后的元素到数组末尾。

using namespace System;

void main()
{
   // Create a string array with 3 elements having the same value.
   array<String^>^ strings = { "the", "quick", "brown", "fox",
                               "jumps", "over", "the", "lazy", "dog",
                               "in", "the", "barn" };

   // Display the elements of the array.
   Console::WriteLine("The array contains the following values:");
   for (int i = strings->GetLowerBound(0); i <= strings->GetUpperBound(0); i++)
      Console::WriteLine("   [{0,2}]: {1}", i, strings[i]);
      
   // Search for the first occurrence of the duplicated value.
   String^ searchString =  "the";
   int index = Array::IndexOf(strings, searchString);
   Console::WriteLine("The first occurrence of \"{0}\" is at index {1}.",
                      searchString, index);

   // Search for the first occurrence of the duplicated value in the last section of the array.
   index = Array::IndexOf( strings, searchString, 4);
   Console::WriteLine("The first occurrence of \"{0}\" between index 4 and the end is at index {1}.",
                      searchString, index);

   // Search for the first occurrence of the duplicated value in a section of the array.
   int position = index + 1;
   index = Array::IndexOf(strings, searchString, position, strings->GetUpperBound(0) - position + 1);
   Console::WriteLine("The first occurrence of \"{0}\" between index {1} and index {2} is at index {3}.",
                      searchString, position, strings->GetUpperBound(0), index);
}
// The example displays 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 first occurrence of "the" is at index 0.
//    The first occurrence of "the" between index 4 and the end is at index 6.
//    The first occurrence of "the" between index 7 and index 11 is at index 10.

// Create a string array with 3 elements having the same value.
let strings = 
    [| "the"; "quick"; "brown"; "fox"; "jumps"; "over"
       "the"; "lazy"; "dog"; "in"; "the"; "barn" |]

// Display the elements of the array.
printfn "The array contains the following values:"
for i = strings.GetLowerBound 0 to strings.GetUpperBound 0 do
    printfn $"   [{i,2}]: {strings[i]}"

// Search for the first occurrence of the duplicated value.
let searchString = "the"
let index = Array.IndexOf(strings, searchString)
printfn $"The first occurrence of \"{searchString}\" is at index {index}."

// Search for the first occurrence of the duplicated value in the last section of the array.
let index = Array.IndexOf(strings, searchString, 4)
printfn $"The first occurrence of \"{searchString}\" between index 4 and the end is at index {index}."

// Search for the first occurrence of the duplicated value in a section of the array.
let position = index + 1
let index = Array.IndexOf(strings, searchString, position, strings.GetUpperBound 0 - position + 1)
printfn $"The first occurrence of \"{searchString}\" between index {position} and index {strings.GetUpperBound 0} is at index {index}."

// The example displays 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 first occurrence of "the" is at index 0.
//    The first occurrence of "the" between index 4 and the end is at index 6.
//    The first occurrence of "the" between index 7 and index 11 is at index 10.

// Create a string array with 3 elements having the same value.
String[] strings = { "the", "quick", "brown", "fox", "jumps",
                     "over", "the", "lazy", "dog", "in", "the",
                     "barn" };

// Display the elements of the array.
Console.WriteLine("The array contains the following values:");
for (int i = strings.GetLowerBound(0); i <= strings.GetUpperBound(0); i++)
   Console.WriteLine("   [{0,2}]: {1}", i, strings[i]);

// Search for the first occurrence of the duplicated value.
string searchString = "the";
int index = Array.IndexOf(strings, searchString);
Console.WriteLine("The first occurrence of \"{0}\" is at index {1}.",
                  searchString, index);

// Search for the first occurrence of the duplicated value in the last section of the array.
index = Array.IndexOf(strings, searchString, 4);
Console.WriteLine("The first occurrence of \"{0}\" between index 4 and the end is at index {1}.",
                  searchString, index);

// Search for the first occurrence of the duplicated value in a section of the array.
int position = index + 1;
index = Array.IndexOf(strings, searchString, position, strings.GetUpperBound(0) - position + 1);
Console.WriteLine("The first occurrence of \"{0}\" between index {1} and index {2} is at index {3}.",
                  searchString, position, strings.GetUpperBound(0), index);

// The example displays 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 first occurrence of "the" is at index 0.
//    The first occurrence of "the" between index 4 and the end is at index 6.
//    The first occurrence of "the" between index 7 and index 11 is at index 10.

Public Module Example
   Public Sub Main()
      ' Create a string array with 3 elements having the same value.
      Dim strings() As String = { "the", "quick", "brown", "fox",
                                  "jumps", "over", "the", "lazy",
                                  "dog", "in", "the", "barn" }

      ' Display the values of the array.
      Console.WriteLine("The array contains the following values:")
      For i As Integer = strings.GetLowerBound(0) To strings.GetUpperBound(0)
         Console.WriteLine("   [{0,2}]: {1}", i, strings(i))
      Next

      ' Search for the first occurrence of the duplicated value.
      Dim searchString As String = "the"
      Dim index As Integer = Array.IndexOf(strings, searchString)
      Console.WriteLine("The first occurrence of ""{0}"" is at index {1}.",
                        searchString, index)
        
      ' Search for the first occurrence of the duplicated value in the last section of the array.
      index = Array.IndexOf(strings, searchString, 4)
      Console.WriteLine("The first occurrence of ""{0}"" between index 4 and the end is at index {1}.",
                        searchString, index)
        
      ' Search for the first occurrence of the duplicated value in a section of the array.
       Dim position As Integer = index + 1
       index = Array.IndexOf(strings, searchString, position, strings.GetUpperBound(0) - position + 1)
       Console.WriteLine("The first occurrence of ""{0}"" between index {1} and index {2} is at index {3}.",
                         searchString, position, strings.GetUpperBound(0), index)
    End Sub
End Module
' The example displays 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 first occurrence of "the" is at index 0.
'    The first occurrence of "the" between index 4 and the end is at index 6.
'    The first occurrence of "the" between index 7 and index 11 is at index 10.

注解

此方法搜索一维数组 value的所有元素。若要确定中array是否存在value，方法通过调用每个元素的 Equals 方法执行相等比较，直到找到匹配项。这意味着，如果元素替代 Object.Equals(Object) 方法，则会调用该替代。

由于大多数数组的下限为零，如果value 找不到，此方法通常返回 -1。在极少数情况下，数组的下限等于 Int32.MinValue (0x80000000) 且 value 找不到，此方法将 Int32.MaxValue 返回 (0x7FFFFFFF) 。

此方法是 O (n) 操作，其中 n 是 Length 的 array。

另请参阅

LastIndexOf

适用于

IndexOf(Array, Object, Int32)

Source:: Array.cs

Source:: Array.cs

Source:: Array.cs

在一个一维数组的一系列元素中搜索指定对象，然后返回其首个匹配项的索引。范围从指定索引到该数组结尾。

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

public static int IndexOf (Array array, object value, int startIndex);

public static int IndexOf (Array array, object? value, int startIndex);

static member IndexOf : Array * obj * int -> int

Public Shared Function IndexOf (array As Array, value As Object, startIndex As Integer) As Integer

参数

array: Array

要搜索的一维数组。

value: Object

要在 array 中查找的对象。

startIndex: Int32

搜索的起始索引。空数组中 0（零）为有效值。

Int32

如果在从 startIndex 到最后一个元素的 array 中的元素范围中找到了 value 的第一个匹配项的索引，则为该索引；否则为数组的下限减 1。

例外

ArgumentNullException

array 为 null。

ArgumentOutOfRangeException

startIndex 超出了 array 的有效索引范围。

RankException

array 是多维的。

示例

该示例调用方法的 IndexOf 以下三个重载，以查找字符串数组中字符串的索引：

IndexOf(Array, Object)，确定字符串数组中字符串“the”的第一个匹配项。
IndexOf(Array, Object, Int32)，用于确定字符串数组的第四个元素到最后一个元素中的字符串“the”的第一个匹配项。
IndexOf(Array, Object, Int32, Int32)，用于确定字符串数组中字符串“the”的第一个匹配项，该字符串从最后一个成功匹配项之后的元素到数组末尾。

using namespace System;

void main()
{
   // Create a string array with 3 elements having the same value.
   array<String^>^ strings = { "the", "quick", "brown", "fox",
                               "jumps", "over", "the", "lazy", "dog",
                               "in", "the", "barn" };

   // Display the elements of the array.
   Console::WriteLine("The array contains the following values:");
   for (int i = strings->GetLowerBound(0); i <= strings->GetUpperBound(0); i++)
      Console::WriteLine("   [{0,2}]: {1}", i, strings[i]);
      
   // Search for the first occurrence of the duplicated value.
   String^ searchString =  "the";
   int index = Array::IndexOf(strings, searchString);
   Console::WriteLine("The first occurrence of \"{0}\" is at index {1}.",
                      searchString, index);

   // Search for the first occurrence of the duplicated value in the last section of the array.
   index = Array::IndexOf( strings, searchString, 4);
   Console::WriteLine("The first occurrence of \"{0}\" between index 4 and the end is at index {1}.",
                      searchString, index);

   // Search for the first occurrence of the duplicated value in a section of the array.
   int position = index + 1;
   index = Array::IndexOf(strings, searchString, position, strings->GetUpperBound(0) - position + 1);
   Console::WriteLine("The first occurrence of \"{0}\" between index {1} and index {2} is at index {3}.",
                      searchString, position, strings->GetUpperBound(0), index);
}
// The example displays 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 first occurrence of "the" is at index 0.
//    The first occurrence of "the" between index 4 and the end is at index 6.
//    The first occurrence of "the" between index 7 and index 11 is at index 10.

// Create a string array with 3 elements having the same value.
let strings = 
    [| "the"; "quick"; "brown"; "fox"; "jumps"; "over"
       "the"; "lazy"; "dog"; "in"; "the"; "barn" |]

// Display the elements of the array.
printfn "The array contains the following values:"
for i = strings.GetLowerBound 0 to strings.GetUpperBound 0 do
    printfn $"   [{i,2}]: {strings[i]}"

// Search for the first occurrence of the duplicated value.
let searchString = "the"
let index = Array.IndexOf(strings, searchString)
printfn $"The first occurrence of \"{searchString}\" is at index {index}."

// Search for the first occurrence of the duplicated value in the last section of the array.
let index = Array.IndexOf(strings, searchString, 4)
printfn $"The first occurrence of \"{searchString}\" between index 4 and the end is at index {index}."

// Search for the first occurrence of the duplicated value in a section of the array.
let position = index + 1
let index = Array.IndexOf(strings, searchString, position, strings.GetUpperBound 0 - position + 1)
printfn $"The first occurrence of \"{searchString}\" between index {position} and index {strings.GetUpperBound 0} is at index {index}."

// The example displays 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 first occurrence of "the" is at index 0.
//    The first occurrence of "the" between index 4 and the end is at index 6.
//    The first occurrence of "the" between index 7 and index 11 is at index 10.

// Create a string array with 3 elements having the same value.
String[] strings = { "the", "quick", "brown", "fox", "jumps",
                     "over", "the", "lazy", "dog", "in", "the",
                     "barn" };

// Display the elements of the array.
Console.WriteLine("The array contains the following values:");
for (int i = strings.GetLowerBound(0); i <= strings.GetUpperBound(0); i++)
   Console.WriteLine("   [{0,2}]: {1}", i, strings[i]);

// Search for the first occurrence of the duplicated value.
string searchString = "the";
int index = Array.IndexOf(strings, searchString);
Console.WriteLine("The first occurrence of \"{0}\" is at index {1}.",
                  searchString, index);

// Search for the first occurrence of the duplicated value in the last section of the array.
index = Array.IndexOf(strings, searchString, 4);
Console.WriteLine("The first occurrence of \"{0}\" between index 4 and the end is at index {1}.",
                  searchString, index);

// Search for the first occurrence of the duplicated value in a section of the array.
int position = index + 1;
index = Array.IndexOf(strings, searchString, position, strings.GetUpperBound(0) - position + 1);
Console.WriteLine("The first occurrence of \"{0}\" between index {1} and index {2} is at index {3}.",
                  searchString, position, strings.GetUpperBound(0), index);

// The example displays 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 first occurrence of "the" is at index 0.
//    The first occurrence of "the" between index 4 and the end is at index 6.
//    The first occurrence of "the" between index 7 and index 11 is at index 10.

Public Module Example
   Public Sub Main()
      ' Create a string array with 3 elements having the same value.
      Dim strings() As String = { "the", "quick", "brown", "fox",
                                  "jumps", "over", "the", "lazy",
                                  "dog", "in", "the", "barn" }

      ' Display the values of the array.
      Console.WriteLine("The array contains the following values:")
      For i As Integer = strings.GetLowerBound(0) To strings.GetUpperBound(0)
         Console.WriteLine("   [{0,2}]: {1}", i, strings(i))
      Next

      ' Search for the first occurrence of the duplicated value.
      Dim searchString As String = "the"
      Dim index As Integer = Array.IndexOf(strings, searchString)
      Console.WriteLine("The first occurrence of ""{0}"" is at index {1}.",
                        searchString, index)
        
      ' Search for the first occurrence of the duplicated value in the last section of the array.
      index = Array.IndexOf(strings, searchString, 4)
      Console.WriteLine("The first occurrence of ""{0}"" between index 4 and the end is at index {1}.",
                        searchString, index)
        
      ' Search for the first occurrence of the duplicated value in a section of the array.
       Dim position As Integer = index + 1
       index = Array.IndexOf(strings, searchString, position, strings.GetUpperBound(0) - position + 1)
       Console.WriteLine("The first occurrence of ""{0}"" between index {1} and index {2} is at index {3}.",
                         searchString, position, strings.GetUpperBound(0), index)
    End Sub
End Module
' The example displays 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 first occurrence of "the" is at index 0.
'    The first occurrence of "the" between index 4 and the end is at index 6.
'    The first occurrence of "the" between index 7 and index 11 is at index 10.

注解

此方法搜索从索引 startIndex 处的元素到最后一个元素的一维数组。为了确定中array是否存在value，方法通过调用Equals每个元素的方法执行相等比较，直到找到匹配项。这意味着，如果元素替代 Object.Equals(Object) 方法，则会调用该替代。

由于大多数数组的下限为零，如果 value 找不到，此方法通常返回 -1。在极少数情况下，数组的下限等于 Int32.MinValue (0x80000000) 且 value 找不到，此方法将 Int32.MaxValue 返回 (0x7FFFFFFF) 。

如果 startIndex 等于 Array.Length，则方法返回 -1。如果 startIndex 大于 Array.Length，方法将 ArgumentOutOfRangeException引发。

此方法是 O (n) 操作，其中 n 是从 startIndex 到末尾的 array元素数。

另请参阅

适用于

IndexOf(Array, Object, Int32, Int32)

Source:: Array.cs

Source:: Array.cs

Source:: Array.cs

在一个一维数组的一系列元素中搜索指定对象，然后返回其首个匹配项的索引。该元素系列的范围从指定数量的元素的指定索引开始。

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

public static int IndexOf (Array array, object value, int startIndex, int count);

public static int IndexOf (Array array, object? value, int startIndex, int count);

static member IndexOf : Array * obj * int * int -> int

Public Shared Function IndexOf (array As Array, value As Object, startIndex As Integer, count As Integer) As Integer

参数

array: Array

要搜索的一维数组。

value: Object

要在 array 中查找的对象。

startIndex: Int32

搜索的起始索引。空数组中 0（零）为有效值。

count: Int32

要搜索的元素数。

Int32

如果在从索引 startIndex 到 startIndex + count - 1 的 array 中找到了 value 的第一个匹配项的索引，则为该索引；否则为该数组的下限减 1。

例外

ArgumentNullException

array 为 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 中指定有效部分。

RankException

array 是多维的。

示例

该示例调用方法的 IndexOf 以下三个重载，以查找字符串数组中字符串的索引：

IndexOf(Array, Object)，确定字符串数组中字符串“the”的第一个匹配项。
IndexOf(Array, Object, Int32)，用于确定字符串数组的第四个元素到最后一个元素中的字符串“the”的第一个匹配项。
IndexOf(Array, Object, Int32, Int32)，用于确定字符串数组中字符串“the”的第一个匹配项，该字符串从最后一个成功匹配项之后的元素到数组末尾。为了确定参数的值 count ，它会从起始索引中减去数组的上限并加一个。

using namespace System;

void main()
{
   // Create a string array with 3 elements having the same value.
   array<String^>^ strings = { "the", "quick", "brown", "fox",
                               "jumps", "over", "the", "lazy", "dog",
                               "in", "the", "barn" };

   // Display the elements of the array.
   Console::WriteLine("The array contains the following values:");
   for (int i = strings->GetLowerBound(0); i <= strings->GetUpperBound(0); i++)
      Console::WriteLine("   [{0,2}]: {1}", i, strings[i]);
      
   // Search for the first occurrence of the duplicated value.
   String^ searchString =  "the";
   int index = Array::IndexOf(strings, searchString);
   Console::WriteLine("The first occurrence of \"{0}\" is at index {1}.",
                      searchString, index);

   // Search for the first occurrence of the duplicated value in the last section of the array.
   index = Array::IndexOf( strings, searchString, 4);
   Console::WriteLine("The first occurrence of \"{0}\" between index 4 and the end is at index {1}.",
                      searchString, index);

   // Search for the first occurrence of the duplicated value in a section of the array.
   int position = index + 1;
   index = Array::IndexOf(strings, searchString, position, strings->GetUpperBound(0) - position + 1);
   Console::WriteLine("The first occurrence of \"{0}\" between index {1} and index {2} is at index {3}.",
                      searchString, position, strings->GetUpperBound(0), index);
}
// The example displays 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 first occurrence of "the" is at index 0.
//    The first occurrence of "the" between index 4 and the end is at index 6.
//    The first occurrence of "the" between index 7 and index 11 is at index 10.

// Create a string array with 3 elements having the same value.
let strings = 
    [| "the"; "quick"; "brown"; "fox"; "jumps"; "over"
       "the"; "lazy"; "dog"; "in"; "the"; "barn" |]

// Display the elements of the array.
printfn "The array contains the following values:"
for i = strings.GetLowerBound 0 to strings.GetUpperBound 0 do
    printfn $"   [{i,2}]: {strings[i]}"

// Search for the first occurrence of the duplicated value.
let searchString = "the"
let index = Array.IndexOf(strings, searchString)
printfn $"The first occurrence of \"{searchString}\" is at index {index}."

// Search for the first occurrence of the duplicated value in the last section of the array.
let index = Array.IndexOf(strings, searchString, 4)
printfn $"The first occurrence of \"{searchString}\" between index 4 and the end is at index {index}."

// Search for the first occurrence of the duplicated value in a section of the array.
let position = index + 1
let index = Array.IndexOf(strings, searchString, position, strings.GetUpperBound 0 - position + 1)
printfn $"The first occurrence of \"{searchString}\" between index {position} and index {strings.GetUpperBound 0} is at index {index}."

// The example displays 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 first occurrence of "the" is at index 0.
//    The first occurrence of "the" between index 4 and the end is at index 6.
//    The first occurrence of "the" between index 7 and index 11 is at index 10.

// Create a string array with 3 elements having the same value.
String[] strings = { "the", "quick", "brown", "fox", "jumps",
                     "over", "the", "lazy", "dog", "in", "the",
                     "barn" };

// Display the elements of the array.
Console.WriteLine("The array contains the following values:");
for (int i = strings.GetLowerBound(0); i <= strings.GetUpperBound(0); i++)
   Console.WriteLine("   [{0,2}]: {1}", i, strings[i]);

// Search for the first occurrence of the duplicated value.
string searchString = "the";
int index = Array.IndexOf(strings, searchString);
Console.WriteLine("The first occurrence of \"{0}\" is at index {1}.",
                  searchString, index);

// Search for the first occurrence of the duplicated value in the last section of the array.
index = Array.IndexOf(strings, searchString, 4);
Console.WriteLine("The first occurrence of \"{0}\" between index 4 and the end is at index {1}.",
                  searchString, index);

// Search for the first occurrence of the duplicated value in a section of the array.
int position = index + 1;
index = Array.IndexOf(strings, searchString, position, strings.GetUpperBound(0) - position + 1);
Console.WriteLine("The first occurrence of \"{0}\" between index {1} and index {2} is at index {3}.",
                  searchString, position, strings.GetUpperBound(0), index);

// The example displays 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 first occurrence of "the" is at index 0.
//    The first occurrence of "the" between index 4 and the end is at index 6.
//    The first occurrence of "the" between index 7 and index 11 is at index 10.

Public Module Example
   Public Sub Main()
      ' Create a string array with 3 elements having the same value.
      Dim strings() As String = { "the", "quick", "brown", "fox",
                                  "jumps", "over", "the", "lazy",
                                  "dog", "in", "the", "barn" }

      ' Display the values of the array.
      Console.WriteLine("The array contains the following values:")
      For i As Integer = strings.GetLowerBound(0) To strings.GetUpperBound(0)
         Console.WriteLine("   [{0,2}]: {1}", i, strings(i))
      Next

      ' Search for the first occurrence of the duplicated value.
      Dim searchString As String = "the"
      Dim index As Integer = Array.IndexOf(strings, searchString)
      Console.WriteLine("The first occurrence of ""{0}"" is at index {1}.",
                        searchString, index)
        
      ' Search for the first occurrence of the duplicated value in the last section of the array.
      index = Array.IndexOf(strings, searchString, 4)
      Console.WriteLine("The first occurrence of ""{0}"" between index 4 and the end is at index {1}.",
                        searchString, index)
        
      ' Search for the first occurrence of the duplicated value in a section of the array.
       Dim position As Integer = index + 1
       index = Array.IndexOf(strings, searchString, position, strings.GetUpperBound(0) - position + 1)
       Console.WriteLine("The first occurrence of ""{0}"" between index {1} and index {2} is at index {3}.",
                         searchString, position, strings.GetUpperBound(0), index)
    End Sub
End Module
' The example displays 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 first occurrence of "the" is at index 0.
'    The first occurrence of "the" between index 4 and the end is at index 6.
'    The first occurrence of "the" between index 7 and index 11 is at index 10.

注解

如果大于 0，则此方法搜索一维数组的元素（startIndex从 count 到 startIndex 加count减 1）。为了确定中array是否存在value，方法通过调用Equals每个元素的方法执行相等比较，直到找到匹配项。这意味着，如果元素替代 Object.Equals 方法，则会调用该替代。

由于大多数数组的下限为零，因此此方法通常在找不到时 value 返回 -1。在极少数情况下，数组的下限等于 Int32.MinValue (0x80000000) 且 value 找不到，此方法返回 Int32.MaxValue (0x7FFFFFFF) 。

如果 startindex 等于 Array.Length，则方法返回 -1。如果 startIndex 大于 Array.Length，方法将 ArgumentOutOfRangeException引发。

此方法是 O (n) 操作，其中 n 为 count。

另请参阅

适用于

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

Source:: Array.cs

Source:: Array.cs

Source:: Array.cs

在一个一维数组的一系列元素中搜索指定对象，然后返回其首个匹配项的索引。范围从指定索引到该数组结尾。

public:
generic <typename T>
 static int IndexOf(cli::array <T> ^ array, T value, int startIndex);

public static int IndexOf<T> (T[] array, T value, int startIndex);

static member IndexOf : 'T[] * 'T * int -> int

Public Shared Function IndexOf(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数组。

value: T

要在 array 中查找的对象。

startIndex: Int32

从零开始的搜索的起始索引。空数组中 0（零）为有效值。

Int32

如果在 value 中从 array 到最后一个元素这部分元素中找到 startIndex 的匹配项，则为第一个匹配项的从零开始的索引；否则为 -1。

例外

ArgumentNullException

array 为 null。

ArgumentOutOfRangeException

startIndex 超出了 array 的有效索引范围。

示例

以下示例演示方法的所有三个 IndexOf 泛型重载。创建字符串数组，其中一个条目在索引位置 0 和索引位置 5 出现两次。方法 IndexOf<T>(T[], T) 重载从开头搜索数组，并找到字符串的第一个匹配项。方法 IndexOf<T>(T[], T, Int32) 重载用于搜索从索引位置 3 开始并一到数组末尾的数组，并查找字符串的第二个匹配项。最后， IndexOf<T>(T[], T, Int32, Int32) 方法重载用于从索引位置 2 开始搜索包含两个条目的范围;它返回 -1，因为该范围内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.IndexOf(dinosaurs, \"Tyrannosaurus\"): {0}", 
        Array::IndexOf(dinosaurs, "Tyrannosaurus"));

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

    Console::WriteLine("\nArray.IndexOf(dinosaurs, \"Tyrannosaurus\", 2, 2): {0}", 
        Array::IndexOf(dinosaurs, "Tyrannosaurus", 2, 2));
}

/* This code example produces the following output:

Tyrannosaurus
Amargasaurus
Mamenchisaurus
Brachiosaurus
Deinonychus
Tyrannosaurus
Compsognathus

Array.IndexOf(dinosaurs, "Tyrannosaurus"): 0

Array.IndexOf(dinosaurs, "Tyrannosaurus", 3): 5

Array.IndexOf(dinosaurs, "Tyrannosaurus", 2, 2): -1
 */

string[] dinosaurs = { "Tyrannosaurus",
    "Amargasaurus",
    "Mamenchisaurus",
    "Brachiosaurus",
    "Deinonychus",
    "Tyrannosaurus",
    "Compsognathus" };

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

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

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

Console.WriteLine(
    "\nArray.IndexOf(dinosaurs, \"Tyrannosaurus\", 2, 2): {0}",
    Array.IndexOf(dinosaurs, "Tyrannosaurus", 2, 2));

/* This code example produces the following output:

Tyrannosaurus
Amargasaurus
Mamenchisaurus
Brachiosaurus
Deinonychus
Tyrannosaurus
Compsognathus

Array.IndexOf(dinosaurs, "Tyrannosaurus"): 0

Array.IndexOf(dinosaurs, "Tyrannosaurus", 3): 5

Array.IndexOf(dinosaurs, "Tyrannosaurus", 2, 2): -1
*/

open System

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

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

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

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

Array.IndexOf(dinosaurs, "Tyrannosaurus", 2, 2)
|> printfn "\nArray.IndexOf(dinosaurs, \"Tyrannosaurus\", 2, 2): %i"

// This code example produces the following output:
//
//    Tyrannosaurus
//    Amargasaurus
//    Mamenchisaurus
//    Brachiosaurus
//    Deinonychus
//    Tyrannosaurus
//    Compsognathus
//    
//    Array.IndexOf(dinosaurs, "Tyrannosaurus"): 0
//
//    Array.IndexOf(dinosaurs, "Tyrannosaurus", 3): 5
//
//    Array.IndexOf(dinosaurs, "Tyrannosaurus", 2, 2): -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.IndexOf(dinosaurs, ""Tyrannosaurus""): {0}", _
            Array.IndexOf(dinosaurs, "Tyrannosaurus"))

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

        Console.WriteLine(vbLf & _
            "Array.IndexOf(dinosaurs, ""Tyrannosaurus"", 2, 2): {0}", _
            Array.IndexOf(dinosaurs, "Tyrannosaurus", 2, 2))

    End Sub
End Class

' This code example produces the following output:
'
'Tyrannosaurus
'Amargasaurus
'Mamenchisaurus
'Brachiosaurus
'Deinonychus
'Tyrannosaurus
'Compsognathus
'
'Array.IndexOf(dinosaurs, "Tyrannosaurus"): 0
'
'Array.IndexOf(dinosaurs, "Tyrannosaurus", 3): 5
'
'Array.IndexOf(dinosaurs, "Tyrannosaurus", 2, 2): -1

注解

此方法从元素 startIndex 到数组末尾搜索一维数组。若要确定中array是否存在value，方法通过对每个元素调用 T.Equals 方法来执行相等比较。这意味着，如果 T 重写 Equals 方法，则会调用该替代。

如果 startIndex 等于 Length，则方法返回 -1。如果 startIndex 大于 Array.Length，该方法将 ArgumentOutOfRangeException引发。

此方法是 O (n) 操作，其中 n 是从到 startIndex 末尾的 array元素数。

另请参阅

适用于

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

Source:: Array.cs

Source:: Array.cs

Source:: Array.cs

在一个一维数组的一系列元素中搜索指定对象，然后返回其首个匹配项的索引。该元素系列的范围从指定数量的元素的指定索引开始。

public:
generic <typename T>
 static int IndexOf(cli::array <T> ^ array, T value, int startIndex, int count);

public static int IndexOf<T> (T[] array, T value, int startIndex, int count);

static member IndexOf : 'T[] * 'T * int * int -> int

Public Shared Function IndexOf(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数组。

value: T

要在 array 中查找的对象。

startIndex: Int32

从零开始的搜索的起始索引。空数组中 0（零）为有效值。

count: Int32

要搜索的部分中的元素数。

Int32

如果在从 count 开始并且包含 startIndex 中指定元素数量的 array 元素范围中找到了 value 第一个匹配项从零开始的索引，则为该索引；否则为 -1。

例外

ArgumentNullException

array 为 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 中指定有效部分。

示例

下面的示例演示方法的所有三个 IndexOf 泛型重载。创建一个字符串数组，其中一个条目在索引位置 0 和索引位置 5 出现两次。方法 IndexOf<T>(T[], T) 重载从头开始搜索数组，并查找字符串的第一个匹配项。方法 IndexOf<T>(T[], T, Int32) 重载用于搜索从索引位置 3 开始的数组，并持续到数组末尾，并查找字符串的第二个匹配项。最后， IndexOf<T>(T[], T, Int32, Int32) 方法重载用于从索引位置 2 开始搜索包含两个条目的范围;它返回 -1，因为该范围内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.IndexOf(dinosaurs, \"Tyrannosaurus\"): {0}", 
        Array::IndexOf(dinosaurs, "Tyrannosaurus"));

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

    Console::WriteLine("\nArray.IndexOf(dinosaurs, \"Tyrannosaurus\", 2, 2): {0}", 
        Array::IndexOf(dinosaurs, "Tyrannosaurus", 2, 2));
}

/* This code example produces the following output:

Tyrannosaurus
Amargasaurus
Mamenchisaurus
Brachiosaurus
Deinonychus
Tyrannosaurus
Compsognathus

Array.IndexOf(dinosaurs, "Tyrannosaurus"): 0

Array.IndexOf(dinosaurs, "Tyrannosaurus", 3): 5

Array.IndexOf(dinosaurs, "Tyrannosaurus", 2, 2): -1
 */

string[] dinosaurs = { "Tyrannosaurus",
    "Amargasaurus",
    "Mamenchisaurus",
    "Brachiosaurus",
    "Deinonychus",
    "Tyrannosaurus",
    "Compsognathus" };

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

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

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

Console.WriteLine(
    "\nArray.IndexOf(dinosaurs, \"Tyrannosaurus\", 2, 2): {0}",
    Array.IndexOf(dinosaurs, "Tyrannosaurus", 2, 2));

/* This code example produces the following output:

Tyrannosaurus
Amargasaurus
Mamenchisaurus
Brachiosaurus
Deinonychus
Tyrannosaurus
Compsognathus

Array.IndexOf(dinosaurs, "Tyrannosaurus"): 0

Array.IndexOf(dinosaurs, "Tyrannosaurus", 3): 5

Array.IndexOf(dinosaurs, "Tyrannosaurus", 2, 2): -1
*/

open System

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

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

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

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

Array.IndexOf(dinosaurs, "Tyrannosaurus", 2, 2)
|> printfn "\nArray.IndexOf(dinosaurs, \"Tyrannosaurus\", 2, 2): %i"

// This code example produces the following output:
//
//    Tyrannosaurus
//    Amargasaurus
//    Mamenchisaurus
//    Brachiosaurus
//    Deinonychus
//    Tyrannosaurus
//    Compsognathus
//    
//    Array.IndexOf(dinosaurs, "Tyrannosaurus"): 0
//
//    Array.IndexOf(dinosaurs, "Tyrannosaurus", 3): 5
//
//    Array.IndexOf(dinosaurs, "Tyrannosaurus", 2, 2): -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.IndexOf(dinosaurs, ""Tyrannosaurus""): {0}", _
            Array.IndexOf(dinosaurs, "Tyrannosaurus"))

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

        Console.WriteLine(vbLf & _
            "Array.IndexOf(dinosaurs, ""Tyrannosaurus"", 2, 2): {0}", _
            Array.IndexOf(dinosaurs, "Tyrannosaurus", 2, 2))

    End Sub
End Class

' This code example produces the following output:
'
'Tyrannosaurus
'Amargasaurus
'Mamenchisaurus
'Brachiosaurus
'Deinonychus
'Tyrannosaurus
'Compsognathus
'
'Array.IndexOf(dinosaurs, "Tyrannosaurus"): 0
'
'Array.IndexOf(dinosaurs, "Tyrannosaurus", 3): 5
'
'Array.IndexOf(dinosaurs, "Tyrannosaurus", 2, 2): -1

注解

如果大于 0，则此方法搜索一维数组的元素（startIndex从 count 到 startIndex 加count减 1）。若要确定中array是否存在value，方法通过对每个元素调用 T.Equals 方法来执行相等比较。这意味着，如果 T 重写 Equals 方法，则会调用该替代。

如果 startIndex 等于 Array.Length，则该方法返回 -1。如果 startIndex 大于 Array.Length，该方法将 ArgumentOutOfRangeException引发。

此方法是 O (n) 操作，其中 n 为 count。

另请参阅

适用于

IndexOf<T>(T[], T)

Source:: Array.cs

Source:: Array.cs

Source:: Array.cs

在一个一维数组中搜索指定对象，并返回其首个匹配项的索引。

public:
generic <typename T>
 static int IndexOf(cli::array <T> ^ array, T value);

public static int IndexOf<T> (T[] array, T value);

static member IndexOf : 'T[] * 'T -> int

Public Shared Function IndexOf(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数组。

value: T

要在 array 中查找的对象。

Int32

如果在整个 array 中找到 value 的第一个匹配项，则为该项的从零开始的索引；否则为 -1。

例外

ArgumentNullException

array 为 null。

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.IndexOf(dinosaurs, \"Tyrannosaurus\"): {0}", 
        Array::IndexOf(dinosaurs, "Tyrannosaurus"));

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

    Console::WriteLine("\nArray.IndexOf(dinosaurs, \"Tyrannosaurus\", 2, 2): {0}", 
        Array::IndexOf(dinosaurs, "Tyrannosaurus", 2, 2));
}

/* This code example produces the following output:

Tyrannosaurus
Amargasaurus
Mamenchisaurus
Brachiosaurus
Deinonychus
Tyrannosaurus
Compsognathus

Array.IndexOf(dinosaurs, "Tyrannosaurus"): 0

Array.IndexOf(dinosaurs, "Tyrannosaurus", 3): 5

Array.IndexOf(dinosaurs, "Tyrannosaurus", 2, 2): -1
 */

string[] dinosaurs = { "Tyrannosaurus",
    "Amargasaurus",
    "Mamenchisaurus",
    "Brachiosaurus",
    "Deinonychus",
    "Tyrannosaurus",
    "Compsognathus" };

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

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

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

Console.WriteLine(
    "\nArray.IndexOf(dinosaurs, \"Tyrannosaurus\", 2, 2): {0}",
    Array.IndexOf(dinosaurs, "Tyrannosaurus", 2, 2));

/* This code example produces the following output:

Tyrannosaurus
Amargasaurus
Mamenchisaurus
Brachiosaurus
Deinonychus
Tyrannosaurus
Compsognathus

Array.IndexOf(dinosaurs, "Tyrannosaurus"): 0

Array.IndexOf(dinosaurs, "Tyrannosaurus", 3): 5

Array.IndexOf(dinosaurs, "Tyrannosaurus", 2, 2): -1
*/

open System

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

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

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

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

Array.IndexOf(dinosaurs, "Tyrannosaurus", 2, 2)
|> printfn "\nArray.IndexOf(dinosaurs, \"Tyrannosaurus\", 2, 2): %i"

// This code example produces the following output:
//
//    Tyrannosaurus
//    Amargasaurus
//    Mamenchisaurus
//    Brachiosaurus
//    Deinonychus
//    Tyrannosaurus
//    Compsognathus
//    
//    Array.IndexOf(dinosaurs, "Tyrannosaurus"): 0
//
//    Array.IndexOf(dinosaurs, "Tyrannosaurus", 3): 5
//
//    Array.IndexOf(dinosaurs, "Tyrannosaurus", 2, 2): -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.IndexOf(dinosaurs, ""Tyrannosaurus""): {0}", _
            Array.IndexOf(dinosaurs, "Tyrannosaurus"))

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

        Console.WriteLine(vbLf & _
            "Array.IndexOf(dinosaurs, ""Tyrannosaurus"", 2, 2): {0}", _
            Array.IndexOf(dinosaurs, "Tyrannosaurus", 2, 2))

    End Sub
End Class

' This code example produces the following output:
'
'Tyrannosaurus
'Amargasaurus
'Mamenchisaurus
'Brachiosaurus
'Deinonychus
'Tyrannosaurus
'Compsognathus
'
'Array.IndexOf(dinosaurs, "Tyrannosaurus"): 0
'
'Array.IndexOf(dinosaurs, "Tyrannosaurus", 3): 5
'
'Array.IndexOf(dinosaurs, "Tyrannosaurus", 2, 2): -1

注解

此方法搜索一维数组 value的所有元素。若要确定中array是否存在value，方法通过对每个元素调用 T.Equals 方法来执行相等比较。这意味着，如果 T 重写 Equals 方法，则会调用该替代。

此方法是 O (n) 操作，其中 n 是 Length 的 array。

另请参阅

适用于

Array.IndexOf 方法

定义

重载

IndexOf(Array, Object)

参数

返回

例外

示例

注解

另请参阅

适用于

IndexOf(Array, Object, Int32)

参数

返回

例外

示例

注解

另请参阅

适用于

IndexOf(Array, Object, Int32, Int32)

参数

返回

例外

示例

注解

另请参阅

适用于

IndexOf<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

IndexOf<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

IndexOf<T>(T[], T)

类型参数

参数

返回

例外

示例

注解

另请参阅

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