ArrayList.LastIndexOf Метод

Определение

Возвращает отсчитываемый от нуля индекс последнего вхождения значения в списке ArrayList или в его части.Returns the zero-based index of the last occurrence of a value in the ArrayList or in a portion of it.

Перегрузки

LastIndexOf(Object)

Осуществляет поиск указанного объекта Object и возвращает отсчитываемый от нуля индекс последнего вхождения в коллекцию ArrayList.Searches for the specified Object and returns the zero-based index of the last occurrence within the entire ArrayList.

LastIndexOf(Object, Int32)

Осуществляет поиск указанного объекта Object и возвращает отсчитываемый от нуля индекс последнего вхождения в диапазоне элементов списка ArrayList, начиная с первого элемента и заканчивая элементом с заданным индексом.Searches for the specified Object and returns the zero-based index of the last occurrence within the range of elements in the ArrayList that extends from the first element to the specified index.

LastIndexOf(Object, Int32, Int32)

Выполняет поиск указанного объекта Object и возвращает отсчитываемый от нуля индекс последнего вхождения в диапазоне элементов списка ArrayList, содержащем указанное число элементов и заканчивающемся в позиции с указанным индексом.Searches for the specified Object and returns the zero-based index of the last occurrence within the range of elements in the ArrayList that contains the specified number of elements and ends at the specified index.

LastIndexOf(Object)

Осуществляет поиск указанного объекта Object и возвращает отсчитываемый от нуля индекс последнего вхождения в коллекцию ArrayList.Searches for the specified Object and returns the zero-based index of the last occurrence within the entire ArrayList.

public:
 virtual int LastIndexOf(System::Object ^ value);
public virtual int LastIndexOf (object value);
abstract member LastIndexOf : obj -> int
override this.LastIndexOf : obj -> int
Public Overridable Function LastIndexOf (value As Object) As Integer

Параметры

value
Object

Объект Object, который требуется найти в коллекции ArrayList.The Object to locate in the ArrayList. Допускается значение null.The value can be null.

Возвраты

Отсчитываемый от нуля индекс последнего вхождения value в пределах всего списка ArrayList, если элемент найден; в противном случае значение –1.The zero-based index of the last occurrence of value within the entire the ArrayList, if found; otherwise, -1.

Примеры

В следующем примере кода показано, как определить индекс последнего вхождения указанного элемента.The following code example shows how to determine the index of the last occurrence of a specified element.

using namespace System;
using namespace System::Collections;
void PrintIndexAndValues( IEnumerable^ myList );
int main()
{
   
   // Creates and initializes a new ArrayList with three elements of the same value.
   ArrayList^ myAL = gcnew ArrayList;
   myAL->Add( "the" );
   myAL->Add( "quick" );
   myAL->Add( "brown" );
   myAL->Add( "fox" );
   myAL->Add( "jumps" );
   myAL->Add( "over" );
   myAL->Add( "the" );
   myAL->Add( "lazy" );
   myAL->Add( "dog" );
   myAL->Add( "in" );
   myAL->Add( "the" );
   myAL->Add( "barn" );
   
   // Displays the values of the ArrayList.
   Console::WriteLine( "The ArrayList contains the following values:" );
   PrintIndexAndValues( myAL );
   
   // Searches for the last occurrence of the duplicated value.
   String^ myString = "the";
   int myIndex = myAL->LastIndexOf( 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 ArrayList.
   myIndex = myAL->LastIndexOf( 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 ArrayList.  Note that the start index is greater than the end index because the search is done backward.
   myIndex = myAL->LastIndexOf( myString, 10, 6 );
   Console::WriteLine( "The last occurrence of \"{0}\" between index 10 and index 5 is at index {1}.", myString, myIndex );
}

void PrintIndexAndValues( IEnumerable^ myList )
{
   int i = 0;
   IEnumerator^ myEnum = myList->GetEnumerator();
   while ( myEnum->MoveNext() )
   {
      Object^ obj = safe_cast<Object^>(myEnum->Current);
      Console::WriteLine( "   [{0}]:    {1}", i++, obj );
   }

   Console::WriteLine();
}

/*
 This code produces the following output.
 
 The ArrayList 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 10 and index 5 is at index 10.
 */
using System;
using System.Collections;
public class SamplesArrayList  {

   public static void Main()  {

      // Creates and initializes a new ArrayList with three elements of the same value.
      ArrayList myAL = new ArrayList();
      myAL.Add( "the" );
      myAL.Add( "quick" );
      myAL.Add( "brown" );
      myAL.Add( "fox" );
      myAL.Add( "jumps" );
      myAL.Add( "over" );
      myAL.Add( "the" );
      myAL.Add( "lazy" );
      myAL.Add( "dog" );
      myAL.Add( "in" );
      myAL.Add( "the" );
      myAL.Add( "barn" );

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

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

   public static void PrintIndexAndValues( IEnumerable myList )  {
      int i = 0;
      foreach ( Object obj in myList )
         Console.WriteLine( "   [{0}]:    {1}", i++, obj );
      Console.WriteLine();
   }

}


/*
This code produces the following output.

The ArrayList 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 10 and index 5 is at index 10.
*/ 
Imports System.Collections

Public Class SamplesArrayList
   
   Public Shared Sub Main()
      
      ' Creates and initializes a new ArrayList with three elements of the same value.
      Dim myAL As New ArrayList()
      myAL.Add("the")
      myAL.Add("quick")
      myAL.Add("brown")
      myAL.Add("fox")
      myAL.Add("jumps")
      myAL.Add("over")
      myAL.Add("the")
      myAL.Add("lazy")
      myAL.Add("dog")
      myAL.Add("in")
      myAL.Add("the")
      myAL.Add("barn")
      
      ' Displays the values of the ArrayList.
      Console.WriteLine("The ArrayList contains the following values:")
      PrintIndexAndValues(myAL)
      
      ' Searches for the last occurrence of the duplicated value.
      Dim myString As [String] = "the"
      Dim myIndex As Integer = myAL.LastIndexOf(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 ArrayList.
      myIndex = myAL.LastIndexOf(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 ArrayList.  Note that the start index is greater than the end index because the search is done backward.
      myIndex = myAL.LastIndexOf(myString, 10, 6)
      Console.WriteLine("The last occurrence of ""{0}"" between index 10 and index 5 is at index {1}.", myString, myIndex)
   End Sub
   
   
   Public Shared Sub PrintIndexAndValues(myList As IEnumerable)
      Dim i as Integer
      Dim obj As [Object]
      For Each obj In  myList
         Console.WriteLine("   [{0}]:    {1}", i, obj)
         i = i + 1
      Next obj
      Console.WriteLine()
   End Sub

End Class

' This code produces the following output.
'
' The ArrayList 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 10 and index 5 is at index 10.

Комментарии

@No__t-0 ищется в обратном направлении, начиная с последнего элемента и заканчивая первым.The ArrayList is searched backward starting at the last element and ending at the first element.

Этот метод выполняет линейный поиск. Таким образом, этот метод является операцией O(n), где nCount.This method performs a linear search; therefore, this method is an O(n) operation, where n is Count.

Начиная с .NET Framework 2,0, этот метод использует методы Equals и CompareTo коллекции для item, чтобы определить, существует ли элемент.Starting with the .NET Framework 2.0, this method uses the collection's objects' Equals and CompareTo methods on item to determine whether item exists. В более ранних версиях .NET Framework это определение было выполнено с помощью методов Equals и CompareTo параметра item для объектов в коллекции.In the earlier versions of the .NET Framework, this determination was made by using the Equals and CompareTo methods of the item parameter on the objects in the collection.

Дополнительно

LastIndexOf(Object, Int32)

Осуществляет поиск указанного объекта Object и возвращает отсчитываемый от нуля индекс последнего вхождения в диапазоне элементов списка ArrayList, начиная с первого элемента и заканчивая элементом с заданным индексом.Searches for the specified Object and returns the zero-based index of the last occurrence within the range of elements in the ArrayList that extends from the first element to the specified index.

public:
 virtual int LastIndexOf(System::Object ^ value, int startIndex);
public virtual int LastIndexOf (object value, int startIndex);
abstract member LastIndexOf : obj * int -> int
override this.LastIndexOf : obj * int -> int
Public Overridable Function LastIndexOf (value As Object, startIndex As Integer) As Integer

Параметры

value
Object

Объект Object, который требуется найти в коллекции ArrayList.The Object to locate in the ArrayList. Допускается значение null.The value can be null.

startIndex
Int32

Индекс (с нуля) начала диапазона поиска в обратном направлении.The zero-based starting index of the backward search.

Возвраты

Отсчитываемый от нуля индекс последнего вхождения элемента value в диапазоне элементов списка ArrayList, начиная с первого элемента и до позиции startIndex, если элемент найден; в противном случае значение -1.The zero-based index of the last occurrence of value within the range of elements in the ArrayList that extends from the first element to startIndex, if found; otherwise, -1.

Исключения

startIndex находится вне диапазона допустимых индексов для ArrayList.startIndex is outside the range of valid indexes for the ArrayList.

Примеры

В следующем примере кода показано, как определить индекс последнего вхождения указанного элемента.The following code example shows how to determine the index of the last occurrence of a specified element.

using namespace System;
using namespace System::Collections;
void PrintIndexAndValues( IEnumerable^ myList );
int main()
{
   
   // Creates and initializes a new ArrayList with three elements of the same value.
   ArrayList^ myAL = gcnew ArrayList;
   myAL->Add( "the" );
   myAL->Add( "quick" );
   myAL->Add( "brown" );
   myAL->Add( "fox" );
   myAL->Add( "jumps" );
   myAL->Add( "over" );
   myAL->Add( "the" );
   myAL->Add( "lazy" );
   myAL->Add( "dog" );
   myAL->Add( "in" );
   myAL->Add( "the" );
   myAL->Add( "barn" );
   
   // Displays the values of the ArrayList.
   Console::WriteLine( "The ArrayList contains the following values:" );
   PrintIndexAndValues( myAL );
   
   // Searches for the last occurrence of the duplicated value.
   String^ myString = "the";
   int myIndex = myAL->LastIndexOf( 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 ArrayList.
   myIndex = myAL->LastIndexOf( 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 ArrayList.  Note that the start index is greater than the end index because the search is done backward.
   myIndex = myAL->LastIndexOf( myString, 10, 6 );
   Console::WriteLine( "The last occurrence of \"{0}\" between index 10 and index 5 is at index {1}.", myString, myIndex );
}

void PrintIndexAndValues( IEnumerable^ myList )
{
   int i = 0;
   IEnumerator^ myEnum = myList->GetEnumerator();
   while ( myEnum->MoveNext() )
   {
      Object^ obj = safe_cast<Object^>(myEnum->Current);
      Console::WriteLine( "   [{0}]:    {1}", i++, obj );
   }

   Console::WriteLine();
}

/*
 This code produces the following output.
 
 The ArrayList 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 10 and index 5 is at index 10.
 */
using System;
using System.Collections;
public class SamplesArrayList  {

   public static void Main()  {

      // Creates and initializes a new ArrayList with three elements of the same value.
      ArrayList myAL = new ArrayList();
      myAL.Add( "the" );
      myAL.Add( "quick" );
      myAL.Add( "brown" );
      myAL.Add( "fox" );
      myAL.Add( "jumps" );
      myAL.Add( "over" );
      myAL.Add( "the" );
      myAL.Add( "lazy" );
      myAL.Add( "dog" );
      myAL.Add( "in" );
      myAL.Add( "the" );
      myAL.Add( "barn" );

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

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

   public static void PrintIndexAndValues( IEnumerable myList )  {
      int i = 0;
      foreach ( Object obj in myList )
         Console.WriteLine( "   [{0}]:    {1}", i++, obj );
      Console.WriteLine();
   }

}


/*
This code produces the following output.

The ArrayList 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 10 and index 5 is at index 10.
*/ 
Imports System.Collections

Public Class SamplesArrayList
   
   Public Shared Sub Main()
      
      ' Creates and initializes a new ArrayList with three elements of the same value.
      Dim myAL As New ArrayList()
      myAL.Add("the")
      myAL.Add("quick")
      myAL.Add("brown")
      myAL.Add("fox")
      myAL.Add("jumps")
      myAL.Add("over")
      myAL.Add("the")
      myAL.Add("lazy")
      myAL.Add("dog")
      myAL.Add("in")
      myAL.Add("the")
      myAL.Add("barn")
      
      ' Displays the values of the ArrayList.
      Console.WriteLine("The ArrayList contains the following values:")
      PrintIndexAndValues(myAL)
      
      ' Searches for the last occurrence of the duplicated value.
      Dim myString As [String] = "the"
      Dim myIndex As Integer = myAL.LastIndexOf(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 ArrayList.
      myIndex = myAL.LastIndexOf(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 ArrayList.  Note that the start index is greater than the end index because the search is done backward.
      myIndex = myAL.LastIndexOf(myString, 10, 6)
      Console.WriteLine("The last occurrence of ""{0}"" between index 10 and index 5 is at index {1}.", myString, myIndex)
   End Sub
   
   
   Public Shared Sub PrintIndexAndValues(myList As IEnumerable)
      Dim i as Integer
      Dim obj As [Object]
      For Each obj In  myList
         Console.WriteLine("   [{0}]:    {1}", i, obj)
         i = i + 1
      Next obj
      Console.WriteLine()
   End Sub

End Class

' This code produces the following output.
'
' The ArrayList 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 10 and index 5 is at index 10.

Комментарии

@No__t-0 ищется в обратном направлении, начиная с startIndex и заканчивая первым элементом.The ArrayList is searched backward starting at startIndex and ending at the first element.

Этот метод выполняет линейный поиск. Таким образом, этот метод является операцией O(n), где n — число элементов с начала ArrayList до startIndex.This method performs a linear search; therefore, this method is an O(n) operation, where n is the number of elements from the beginning of the ArrayList to startIndex.

Этот метод определяет равенство, вызывая Object.Equals.This method determines equality by calling Object.Equals.

Начиная с .NET Framework 2,0, этот метод использует методы Equals и CompareTo коллекции для item, чтобы определить, существует ли элемент.Starting with the .NET Framework 2.0, this method uses the collection's objects' Equals and CompareTo methods on item to determine whether item exists. В более ранних версиях .NET Framework это определение было выполнено с помощью методов Equals и CompareTo параметра item для объектов в коллекции.In the earlier versions of the .NET Framework, this determination was made by using the Equals and CompareTo methods of the item parameter on the objects in the collection.

Дополнительно

LastIndexOf(Object, Int32, Int32)

Выполняет поиск указанного объекта Object и возвращает отсчитываемый от нуля индекс последнего вхождения в диапазоне элементов списка ArrayList, содержащем указанное число элементов и заканчивающемся в позиции с указанным индексом.Searches for the specified Object and returns the zero-based index of the last occurrence within the range of elements in the ArrayList that contains the specified number of elements and ends at the specified index.

public:
 virtual int LastIndexOf(System::Object ^ value, int startIndex, int count);
public virtual int LastIndexOf (object value, int startIndex, int count);
abstract member LastIndexOf : obj * int * int -> int
override this.LastIndexOf : obj * int * int -> int
Public Overridable Function LastIndexOf (value As Object, startIndex As Integer, count As Integer) As Integer

Параметры

value
Object

Объект Object, который требуется найти в коллекции ArrayList.The Object to locate in the ArrayList. Допускается значение null.The value can be null.

startIndex
Int32

Индекс (с нуля) начала диапазона поиска в обратном направлении.The zero-based starting index of the backward search.

count
Int32

Число элементов в диапазоне, в котором выполняется поиск.The number of elements in the section to search.

Возвраты

Отсчитываемый от нуля индекс последнего вхождения value в диапазоне элементов списка ArrayList, состоящем из count элементов и заканчивающемся в позиции startIndex, если элемент найден. В противном случае значение –1.The zero-based index of the last occurrence of value within the range of elements in the ArrayList that contains count number of elements and ends at startIndex, if found; otherwise, -1.

Исключения

startIndex находится вне диапазона допустимых индексов для ArrayList.startIndex is outside the range of valid indexes for the ArrayList.

- или --or- Значение параметра count меньше нуля.count is less than zero.

-или--or- startIndex и count не указывают допустимый раздел в ArrayList.startIndex and count do not specify a valid section in the ArrayList.

Примеры

В следующем примере кода показано, как определить индекс последнего вхождения указанного элемента.The following code example shows how to determine the index of the last occurrence of a specified element. Обратите внимание, что LastIndexOf является обратным поиском; Таким образом, count должно быть меньше или равно startIndex + 1.Note that LastIndexOf is a backward search; therefore, count must be less than or equal to startIndex + 1.

using namespace System;
using namespace System::Collections;
void PrintIndexAndValues( IEnumerable^ myList );
int main()
{
   
   // Creates and initializes a new ArrayList with three elements of the same value.
   ArrayList^ myAL = gcnew ArrayList;
   myAL->Add( "the" );
   myAL->Add( "quick" );
   myAL->Add( "brown" );
   myAL->Add( "fox" );
   myAL->Add( "jumps" );
   myAL->Add( "over" );
   myAL->Add( "the" );
   myAL->Add( "lazy" );
   myAL->Add( "dog" );
   myAL->Add( "in" );
   myAL->Add( "the" );
   myAL->Add( "barn" );
   
   // Displays the values of the ArrayList.
   Console::WriteLine( "The ArrayList contains the following values:" );
   PrintIndexAndValues( myAL );
   
   // Searches for the last occurrence of the duplicated value.
   String^ myString = "the";
   int myIndex = myAL->LastIndexOf( 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 ArrayList.
   myIndex = myAL->LastIndexOf( 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 ArrayList.  Note that the start index is greater than the end index because the search is done backward.
   myIndex = myAL->LastIndexOf( myString, 10, 6 );
   Console::WriteLine( "The last occurrence of \"{0}\" between index 10 and index 5 is at index {1}.", myString, myIndex );
}

void PrintIndexAndValues( IEnumerable^ myList )
{
   int i = 0;
   IEnumerator^ myEnum = myList->GetEnumerator();
   while ( myEnum->MoveNext() )
   {
      Object^ obj = safe_cast<Object^>(myEnum->Current);
      Console::WriteLine( "   [{0}]:    {1}", i++, obj );
   }

   Console::WriteLine();
}

/*
 This code produces the following output.
 
 The ArrayList 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 10 and index 5 is at index 10.
 */
using System;
using System.Collections;
public class SamplesArrayList  {

   public static void Main()  {

      // Creates and initializes a new ArrayList with three elements of the same value.
      ArrayList myAL = new ArrayList();
      myAL.Add( "the" );
      myAL.Add( "quick" );
      myAL.Add( "brown" );
      myAL.Add( "fox" );
      myAL.Add( "jumps" );
      myAL.Add( "over" );
      myAL.Add( "the" );
      myAL.Add( "lazy" );
      myAL.Add( "dog" );
      myAL.Add( "in" );
      myAL.Add( "the" );
      myAL.Add( "barn" );

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

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

   public static void PrintIndexAndValues( IEnumerable myList )  {
      int i = 0;
      foreach ( Object obj in myList )
         Console.WriteLine( "   [{0}]:    {1}", i++, obj );
      Console.WriteLine();
   }

}


/*
This code produces the following output.

The ArrayList 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 10 and index 5 is at index 10.
*/ 
Imports System.Collections

Public Class SamplesArrayList
   
   Public Shared Sub Main()
      
      ' Creates and initializes a new ArrayList with three elements of the same value.
      Dim myAL As New ArrayList()
      myAL.Add("the")
      myAL.Add("quick")
      myAL.Add("brown")
      myAL.Add("fox")
      myAL.Add("jumps")
      myAL.Add("over")
      myAL.Add("the")
      myAL.Add("lazy")
      myAL.Add("dog")
      myAL.Add("in")
      myAL.Add("the")
      myAL.Add("barn")
      
      ' Displays the values of the ArrayList.
      Console.WriteLine("The ArrayList contains the following values:")
      PrintIndexAndValues(myAL)
      
      ' Searches for the last occurrence of the duplicated value.
      Dim myString As [String] = "the"
      Dim myIndex As Integer = myAL.LastIndexOf(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 ArrayList.
      myIndex = myAL.LastIndexOf(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 ArrayList.  Note that the start index is greater than the end index because the search is done backward.
      myIndex = myAL.LastIndexOf(myString, 10, 6)
      Console.WriteLine("The last occurrence of ""{0}"" between index 10 and index 5 is at index {1}.", myString, myIndex)
   End Sub
   
   
   Public Shared Sub PrintIndexAndValues(myList As IEnumerable)
      Dim i as Integer
      Dim obj As [Object]
      For Each obj In  myList
         Console.WriteLine("   [{0}]:    {1}", i, obj)
         i = i + 1
      Next obj
      Console.WriteLine()
   End Sub

End Class

' This code produces the following output.
'
' The ArrayList 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 10 and index 5 is at index 10.

Комментарии

@No__t-0 ищется в обратном направлении, начиная с startIndex и заканчивая на startIndex минус count плюс 1, если count больше 0.The ArrayList is searched backward starting at startIndex and ending at startIndex minus count plus 1, if count is greater than 0.

Этот метод выполняет линейный поиск. Таким образом, этот метод является операцией O(n), где ncount.This method performs a linear search; therefore, this method is an O(n) operation, where n is count.

Этот метод определяет равенство, вызывая Object.Equals.This method determines equality by calling Object.Equals.

Начиная с .NET Framework 2,0, этот метод использует методы Equals и CompareTo коллекции для item, чтобы определить, существует ли элемент.Starting with the .NET Framework 2.0, this method uses the collection's objects' Equals and CompareTo methods on item to determine whether item exists. В более ранних версиях .NET Framework это определение было выполнено с помощью методов Equals и CompareTo параметра item для объектов в коллекции.In the earlier versions of the .NET Framework, this determination was made by using the Equals and CompareTo methods of the item parameter on the objects in the collection.

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