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

Definition

Namespace:

System.Collections.Generic

Assembly:

System.Collections.dll

Source:

Dictionary.cs

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

Remove(Object)

Exceptions

ArgumentNullException

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");

open System
open System.Collections
open System.Collections.Generic

// Create a new dictionary of strings, with string keys,
// and access it using the IDictionary interface.
let openWith: IDictionary = 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.
printfn "\nRemove(\"dib\")"
openWith.Remove "dib"

if openWith.Contains "dib" |> not then
    printfn "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.