ArrayList.RemoveAt メソッド

[アーティクル]
03/28/2008

ArrayList の指定したインデックスにある要素を削除します。

Public Overridable Sub RemoveAt( _
   ByVal index As Integer _) Implements IList.RemoveAt
[C#]
public virtual void RemoveAt(intindex);
[C++]
public: virtual void RemoveAt(intindex);
[JScript]
public function RemoveAt(
   index : int);

パラメータ

index
削除する要素の、0 から始まるインデックス番号。

実装

IList.RemoveAt

例外

例外の種類	条件
ArgumentOutOfRangeException	index が 0 未満です。または index が Count 以上です。
NotSupportedException	ArrayList が読み取り専用です。または ArrayList が固定サイズです。

ArgumentOutOfRangeException

index が 0 未満です。

または

index が Count 以上です。

NotSupportedException

ArrayList が読み取り専用です。

または

ArrayList が固定サイズです。

解説

リストなどの連続する要素のコレクションでは、空白になった位置を埋めるために、削除された要素の後にある要素の位置が繰り上げられます。インデックス付きのコレクションの場合は、移動した要素のインデックスも更新されます。この動作は、要素が概念的にバケットにグループ化されているハッシュテーブルなどのコレクションには適用されません。

使用例

ArrayList から要素を削除する方法の例を次に示します。

 
Imports System
Imports System.Collections
Imports Microsoft.VisualBasic

Public Class SamplesArrayList    
    
    Public Shared Sub Main()
        
        ' Creates and initializes a new ArrayList.
        Dim myAL As New ArrayList()
        myAL.Add("The")
        myAL.Add("quick")
        myAL.Add("brown")
        myAL.Add("fox")
        myAL.Add("jumped")
        myAL.Add("over")
        myAL.Add("the")
        myAL.Add("lazy")
        myAL.Add("dog")
        
        ' Displays the ArrayList.
        Console.WriteLine("The ArrayList initially contains the following:")
        PrintValues(myAL)
        
        ' Removes the element containing "lazy".
        myAL.Remove("lazy")
        
        ' Displays the current state of the ArrayList.
        Console.WriteLine("After removing ""lazy"":")
        PrintValues(myAL)
        
        ' Removes the element at index 5.
        myAL.RemoveAt(5)
        
        ' Displays the current state of the ArrayList.
        Console.WriteLine("After removing the element at index 5:")
        PrintValues(myAL)
        
        ' Removes three elements starting at index 4.
        myAL.RemoveRange(4, 3)
        
        ' Displays the current state of the ArrayList.
        Console.WriteLine("After removing three elements starting at index 4:")
        PrintValues(myAL)
    End Sub
    
    Public Shared Sub PrintValues(myList As IEnumerable)
        Dim myEnumerator As System.Collections.IEnumerator = _
           myList.GetEnumerator()
        While myEnumerator.MoveNext()
            Console.Write(ControlChars.Tab + "{0}", myEnumerator.Current)
        End While
        Console.WriteLine()
    End Sub
End Class

' This code produces the following output.
' 
' The ArrayList initially contains the following:
'     The    quick    brown    fox    jumped    over    the    lazy    dog
' After removing "lazy":
'     The    quick    brown    fox    jumped    over    the    dog
' After removing the element at index 5:
'     The    quick    brown    fox    jumped    the    dog
' After removing three elements starting at index 4:
'     The    quick    brown    fox 

[C#] 
using System;
using System.Collections;
public class SamplesArrayList  {

   public static void Main()  {

      // Creates and initializes a new ArrayList.
      ArrayList myAL = new ArrayList();
      myAL.Add( "The" );
      myAL.Add( "quick" );
      myAL.Add( "brown" );
      myAL.Add( "fox" );
      myAL.Add( "jumped" );
      myAL.Add( "over" );
      myAL.Add( "the" );
      myAL.Add( "lazy" );
      myAL.Add( "dog" );

      // Displays the ArrayList.
      Console.WriteLine( "The ArrayList initially contains the following:" );
      PrintValues( myAL );

      // Removes the element containing "lazy".
      myAL.Remove( "lazy" );

      // Displays the current state of the ArrayList.
      Console.WriteLine( "After removing \"lazy\":" );
      PrintValues( myAL );

      // Removes the element at index 5.
      myAL.RemoveAt( 5 );

      // Displays the current state of the ArrayList.
      Console.WriteLine( "After removing the element at index 5:" );
      PrintValues( myAL );

      // Removes three elements starting at index 4.
      myAL.RemoveRange( 4, 3 );

      // Displays the current state of the ArrayList.
      Console.WriteLine( "After removing three elements starting at index 4:" );
      PrintValues( myAL );
   }

   public static void PrintValues( IEnumerable myList )  {
      System.Collections.IEnumerator myEnumerator = myList.GetEnumerator();
      while ( myEnumerator.MoveNext() )
         Console.Write( "\t{0}", myEnumerator.Current );
      Console.WriteLine();
   }
}
/* 
This code produces the following output.

The ArrayList initially contains the following:
    The    quick    brown    fox    jumped    over    the    lazy    dog
After removing "lazy":
    The    quick    brown    fox    jumped    over    the    dog
After removing the element at index 5:
    The    quick    brown    fox    jumped    the    dog
After removing three elements starting at index 4:
    The    quick    brown    fox
*/ 

[C++] 
#using <mscorlib.dll>
using namespace System;
using namespace System::Collections;

void PrintValues( IEnumerable* myList );
 
int main()  {
 
       // Creates and initializes a new ArrayList.
       ArrayList* myAL = new ArrayList();
       myAL->Add( S"The" );
       myAL->Add( S"quick" );
       myAL->Add( S"brown" );
       myAL->Add( S"fox" );
       myAL->Add( S"jumped" );
       myAL->Add( S"over" );
       myAL->Add( S"the" );
       myAL->Add( S"lazy" );
       myAL->Add( S"dog" );
 
       // Displays the ArrayList.
       Console::WriteLine( "The ArrayList initially contains the following:" );
       PrintValues( myAL );
 
       // Removes the element containing "lazy".
       myAL->Remove( S"lazy" );
 
       // Displays the current state of the ArrayList.
       Console::WriteLine( "After removing \"lazy\":" );
       PrintValues( myAL );
 
       // Removes the element at index 5.
       myAL->RemoveAt( 5 );
 
       // Displays the current state of the ArrayList.
       Console::WriteLine( "After removing the element at index 5:" );
       PrintValues( myAL );
 
       // Removes three elements starting at index 4.
       myAL->RemoveRange( 4, 3 );
 
       // Displays the current state of the ArrayList.
       Console::WriteLine( "After removing three elements starting at index 4:" );
       PrintValues( myAL );
    }
 
void PrintValues( IEnumerable* myList )  {
       System::Collections::IEnumerator* myEnumerator = myList->GetEnumerator();
       while ( myEnumerator->MoveNext() )
          Console::Write( "\t{0}", myEnumerator->Current );
       Console::WriteLine();
    }

 /* 
 This code produces the following output.
 
The ArrayList initially contains the following:
        The     quick   brown   fox     jumped  over    the     lazy    dog
After removing "lazy":
        The     quick   brown   fox     jumped  over    the     dog
After removing the element at index 5:
        The     quick   brown   fox     jumped  the     dog
After removing three elements starting at index 4:
        The     quick   brown   fox

 */ 

[JScript] 
import System;
import System.Collections;

// Creates and initializes a new ArrayList.
var myAL : ArrayList = new ArrayList();
myAL.Add( "The" );
myAL.Add( "quick" );
myAL.Add( "brown" );
myAL.Add( "fox" );
myAL.Add( "jumped" );
myAL.Add( "over" );
myAL.Add( "the" );
myAL.Add( "lazy" );
myAL.Add( "dog" );

// Displays the ArrayList.
Console.WriteLine( "The ArrayList initially contains the following:" );
PrintValues( myAL );

// Removes the element containing "lazy".
myAL.Remove( "lazy" );

// Displays the current state of the ArrayList.
Console.WriteLine( "After removing \"lazy\":" );
PrintValues( myAL );

// Removes the element at index 5.
myAL.RemoveAt( 5 );

// Displays the current state of the ArrayList.
Console.WriteLine( "After removing the element at index 5:" );
PrintValues( myAL );

// Removes three elements starting at index 4.
myAL.RemoveRange( 4, 3 );

// Displays the current state of the ArrayList.
Console.WriteLine( "After removing three elements starting at index 4:" );
PrintValues( myAL );

function PrintValues( myList : IEnumerable )  {
   var myEnumerator : System.Collections.IEnumerator  = myList.GetEnumerator();
   while ( myEnumerator.MoveNext() )
      Console.Write( "\t{0}", myEnumerator.Current );
   Console.WriteLine();
}
 /* 
 This code produces the following output.
 
 The ArrayList initially contains the following:
     The    quick    brown    fox    jumped    over    the    lazy    dog
 After removing "lazy":
     The    quick    brown    fox    jumped    over    the    dog
 After removing the element at index 5:
     The    quick    brown    fox    jumped    the    dog
 After removing three elements starting at index 4:
     The    quick    brown    fox
 */

必要条件

プラットフォーム: Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 ファミリ, .NET Compact Framework - Windows CE .NET, Common Language Infrastructure (CLI) Standard

参照

次の方法で共有

ArrayList.RemoveAt メソッド

パラメータ

実装

例外

解説

使用例

必要条件

参照

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