ArrayList.Remove メソッド
ArrayList 内で最初に見つかった特定のオブジェクトを削除します。
Public Overridable Sub Remove( _
ByVal obj As Object _) Implements IList.Remove
[C#]
public virtual void Remove(objectobj);
[C++]
public: virtual void Remove(Object* obj);
[JScript]
public function Remove(
obj : Object);
パラメータ
実装
例外
| 例外の種類 | 条件 |
|---|---|
| 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
このメソッドは順次検索を実行します。したがって、平均検索時間は Count に比例します。つまり、このメソッドは O(n) 操作です。ここで、 n は Count です。
このメソッドは、 Object.Equals を呼び出して、等しいかどうかを判断します。
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
ArrayList クラス | ArrayList メンバ | System.Collections 名前空間 | RemoveAt | RemoveRange | Add | Insert | カルチャを認識しないコレクションの操作の実行