Dictionary<TKey,TValue>.IDictionary.Remove(Object) Method

Definition

Removes the element with the specified key from the IDictionary.

 virtual void System.Collections.IDictionary.Remove(System::Object ^ key) = System::Collections::IDictionary::Remove;
void IDictionary.Remove (object key);
abstract member System.Collections.IDictionary.Remove : obj -> unit
override this.System.Collections.IDictionary.Remove : obj -> unit
Sub Remove (key As Object) Implements IDictionary.Remove

Parameters

key
Object

The key of the element to remove.

Implements

Exceptions

key is null.

Examples

The following code example shows how to use the IDictionary.Remove of the System.Collections.IDictionary interface with a Dictionary<TKey,TValue>.

The code example is part of a larger example, including output, provided for the IDictionary.Add method.

using System;
using System.Collections;
using System.Collections.Generic;

public class Example
{
    public static void Main()
    {
        // Create a new dictionary of strings, with string keys,
        // and access it using the IDictionary interface.
        //
        IDictionary openWith = new Dictionary<string, string>();

        // Add some elements to the dictionary. There are no
        // duplicate keys, but some of the values are duplicates.
        // IDictionary.Add throws an exception if incorrect types
        // are supplied for key or value.
        openWith.Add("txt", "notepad.exe");
        openWith.Add("bmp", "paint.exe");
        openWith.Add("dib", "paint.exe");
        openWith.Add("rtf", "wordpad.exe");
Imports System.Collections
Imports System.Collections.Generic

Public Class Example
    
    Public Shared Sub Main() 

        ' Create a new dictionary of strings, with string keys,
        ' and access it using the IDictionary interface.
        '
        Dim openWith As IDictionary = _
            New Dictionary(Of String, String)
        
        ' Add some elements to the dictionary. There are no 
        ' duplicate keys, but some of the values are duplicates.
        ' IDictionary.Add throws an exception if incorrect types
        ' are supplied for key or value.
        openWith.Add("txt", "notepad.exe")
        openWith.Add("bmp", "paint.exe")
        openWith.Add("dib", "paint.exe")
        openWith.Add("rtf", "wordpad.exe")
// Use the Remove method to remove a key/value pair. No
// exception is thrown if the wrong data type is supplied.
Console.WriteLine("\nRemove(\"dib\")");
openWith.Remove("dib");

if (!openWith.Contains("dib"))
{
    Console.WriteLine("Key \"dib\" is not found.");
}
' Use the Remove method to remove a key/value pair. No
' exception is thrown if the wrong data type is supplied.
Console.WriteLine(vbLf + "Remove(""dib"")")
openWith.Remove("dib")

If Not openWith.Contains("dib") Then
    Console.WriteLine("Key ""dib"" is not found.")
End If
    }
}

    End Sub

End Class

Remarks

This method approaches an O(1) operation.

Applies to