ArrayList.RemoveAt Method
Assembly: mscorlib (in mscorlib.dll)
| Exception type | Condition |
|---|---|
| index is less than zero. -or- index is equal to or greater than Count. | |
| The ArrayList is read-only. -or- The ArrayList has a fixed size. |
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.
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( "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 ); } 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 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 */
import System.*;
import System.Collections.*;
public class SamplesArrayList
{
public static void main(String[] args)
{
// 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);
} //main
public static void PrintValues(IEnumerable myList)
{
IEnumerator objMyEnum = myList.GetEnumerator();
while (objMyEnum.MoveNext()) {
Object obj = objMyEnum.get_Current();
Console.Write(" {0}", obj);
}
Console.WriteLine();
} //PrintValues
} //SamplesArrayList
/*
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
*/
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 */
Windows 98, Windows Server 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition
The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.