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ArrayList.RemoveRange(Int32, Int32) Method

Definition

Removes a range of elements from the ArrayList.

public:
 virtual void RemoveRange(int index, int count);
public virtual void RemoveRange (int index, int count);
abstract member RemoveRange : int * int -> unit
override this.RemoveRange : int * int -> unit
Public Overridable Sub RemoveRange (index As Integer, count As Integer)

Parameters

index
Int32

The zero-based starting index of the range of elements to remove.

count
Int32

The number of elements to remove.

Exceptions

index is less than zero.

-or-

count is less than zero.

index and count do not denote a valid range of elements in the ArrayList.

The ArrayList is read-only.

-or-

The ArrayList has a fixed size.

Examples

The following code example shows how to remove elements from the ArrayList.

using namespace System;
using namespace System::Collections;
void PrintValues( IEnumerable^ myList );
int main()
{
   
   // Creates and initializes a new ArrayList.
   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" );
   
   // 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 );
}

void PrintValues( IEnumerable^ myList )
{
   IEnumerator^ myEnum = myList->GetEnumerator();
   while ( myEnum->MoveNext() )
   {
      Object^ obj = safe_cast<Object^>(myEnum->Current);
      Console::Write( "   {0}", obj );
   }

   Console::WriteLine();
}

/* 
 This code produces the following output.
 
 The ArrayList initially contains the following:
    The   quick   brown   fox   jumps   over   the   lazy   dog
 After removing "lazy":
    The   quick   brown   fox   jumps   over   the   dog
 After removing the element at index 5:
    The   quick   brown   fox   jumps   the   dog
 After removing three elements starting at index 4:
    The   quick   brown   fox
 */
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( "jumps" );
      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 )  {
      foreach ( Object obj in myList )
         Console.Write( "   {0}", obj );
      Console.WriteLine();
   }
}
/*
This code produces the following output.

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

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("jumps")
        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 obj As [Object]
        For Each obj In  myList
            Console.Write("   {0}", obj)
        Next obj
        Console.WriteLine()
    End Sub

End Class


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

Remarks

In collections of contiguous elements, such as lists, the elements that follow the removed element move up to occupy the vacated spot. If the collection is indexed, the indexes of the elements that are moved are also updated. This behavior does not apply to collections where elements are conceptually grouped into buckets, such as a hash table.

This method is an O(n) operation, where n is Count.

Applies to

See also