ArrayList.LastIndexOf Método

Referência

Definição

Namespace:: System.Collections

Assemblies:: mscorlib.dll, System.Collections.NonGeneric.dll

Assembly:: System.Runtime.dll

Assembly:: System.Collections.NonGeneric.dll

Assembly:: System.Runtime.Extensions.dll

Assembly:: mscorlib.dll

Assembly:: netstandard.dll

Importante

Algumas informações se referem a produtos de pré-lançamento que podem ser substancialmente modificados antes do lançamento. A Microsoft não oferece garantias, expressas ou implícitas, das informações aqui fornecidas.

Retorna o índice baseado em zero da última ocorrência de um valor no ArrayList ou em uma parte dele.

Sobrecargas

LastIndexOf(Object)	Pesquisa o Object especificado e retorna o índice de base zero da última ocorrência dentro de todo o ArrayList.
LastIndexOf(Object, Int32)	Pesquisa o Object especificado e retorna o índice baseado em zero da última ocorrência dentro do intervalo de elementos no ArrayList que se estende do primeiro elemento ao índice especificado.
LastIndexOf(Object, Int32, Int32)	Pesquisa o Object especificado e retorna o índice baseado em zero da última ocorrência no intervalo de elementos na ArrayList que contém o número de elementos especificado e termina no índice especificado.

LastIndexOf(Object)

Pesquisa o Object especificado e retorna o índice de base zero da última ocorrência dentro de todo o ArrayList.

public:
 virtual int LastIndexOf(System::Object ^ value);

public virtual int LastIndexOf (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

Parâmetros

value: Object

O Object a ser localizado no ArrayList. O valor pode ser null.

Retornos

Int32

O índice de base zero da última ocorrência de value em todo o ArrayList, se localizado; caso contrário, -1.

Exemplos

O exemplo de código a seguir mostra como determinar o índice da última ocorrência de um elemento especificado.

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.

Comentários

O ArrayList é pesquisado para trás começando no último elemento e terminando no primeiro elemento.

Esse método executa uma pesquisa linear; portanto, esse método é uma O(n) operação, onde n está Count.

A partir do .NET Framework 2.0, esse método usa os objetos e CompareTo métodos Equals item da coleção para determinar se o item existe. Em versões anteriores do .NET Framework, essa decisão era tomada usando-se os métodos Equals e CompareTo do parâmetro item nos objetos na coleção.

Confira também

Aplica-se a

LastIndexOf(Object, Int32)

Pesquisa o Object especificado e retorna o índice baseado em zero da última ocorrência dentro do intervalo de elementos no ArrayList que se estende do primeiro elemento ao índice especificado.

public:
 virtual int LastIndexOf(System::Object ^ value, int startIndex);

public virtual int LastIndexOf (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

Parâmetros

value: Object

O Object a ser localizado no ArrayList. O valor pode ser null.

startIndex: Int32

O índice inicial com base em zero da pesquisa inversa.

Retornos

Int32

O índice baseado em zero da última ocorrência de value dentro do intervalo de elementos em ArrayList que se estende do primeiro elemento a startIndex, se encontrado; caso contrário, -1.

Exceções

ArgumentOutOfRangeException

startIndex está fora do intervalo de índices válidos para o ArrayList.

Exemplos

O exemplo de código a seguir mostra como determinar o índice da última ocorrência de um elemento especificado.

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.

Comentários

O ArrayList é pesquisado para trás começando startIndex e terminando no primeiro elemento.

Esse método executa uma pesquisa linear; portanto, esse método é uma O(n) operação, onde n está o número de elementos do início do ArrayList para startIndex.

Este método determina a igualdade chamando Object.Equals.

Confira também

Aplica-se a

LastIndexOf(Object, Int32, Int32)

Pesquisa o Object especificado e retorna o índice baseado em zero da última ocorrência no intervalo de elementos na ArrayList que contém o número de elementos especificado e termina no índice especificado.

public:
 virtual int LastIndexOf(System::Object ^ value, int startIndex, int count);

public virtual int LastIndexOf (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

Parâmetros

value: Object

O Object a ser localizado no ArrayList. O valor pode ser null.

startIndex: Int32

O índice inicial com base em zero da pesquisa inversa.

count: Int32

O número de elementos na seção a ser pesquisada.

Retornos

Int32

O índice baseado em zero da última ocorrência de value dentro do intervalo de elementos no ArrayList que contém o número count de elementos e termina em startIndex, se encontrado; caso contrário, -1.

Exceções

ArgumentOutOfRangeException

startIndex está fora do intervalo de índices válidos para o ArrayList.

- ou - count é menor que zero.

- ou - startIndex e count não especificam uma seção válida no ArrayList.

Exemplos

O exemplo de código a seguir mostra como determinar o índice da última ocorrência de um elemento especificado. Observe que LastIndexOf é uma pesquisa com versões anteriores; portanto, count deve ser menor ou igual a 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.

Comentários

O ArrayList é pesquisado para trás começando startIndex e terminando em startIndex menos count mais 1, se count for maior que 0.

Esse método executa uma pesquisa linear; portanto, esse método é uma O(n) operação, onde n está count.

Este método determina a igualdade chamando Object.Equals.

Confira também

Aplica-se a

ArrayList.LastIndexOf Método

Definição

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LastIndexOf(Object)

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Retornos

Exemplos

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Aplica-se a

LastIndexOf(Object, Int32)

Parâmetros

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Exceções

Exemplos

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Aplica-se a

LastIndexOf(Object, Int32, Int32)

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