Dictionary(TKey, TValue).Remove Method (System.Collections.Generic)

Remove Method

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This page is specific to

Microsoft Visual Studio 2010/.NET Framework 4

Other versions are also available for the following:

.NET Framework Class Library

Dictionary<(Of <(TKey, TValue>)>)..::.Remove Method

Removes the value with the specified key from the Dictionary<(Of <(TKey, TValue>)>).

Namespace: System.Collections.Generic
Assembly: mscorlib (in mscorlib.dll)

Syntax

Visual Basic

Public Function Remove ( _
    key As TKey _
) As Boolean

public bool Remove(
    TKey key
)

Visual C++

public:
virtual bool Remove(
    TKey key
) sealed

abstract Remove : 
        key:'TKey -> bool 
override Remove : 
        key:'TKey -> bool

Parameters

key: Type: TKey
The key of the element to remove.

Return Value

Type: System..::.Boolean
true if the element is successfully found and removed; otherwise, false. This method returns false if key is not found in the Dictionary<(Of <(TKey, TValue>)>).

Implements

IDictionary<(Of <(TKey, TValue>)>)..::.Remove(TKey)

Exceptions

Exception	Condition
ArgumentNullException	key is nullNothingnullptra null reference (Nothing in Visual Basic).

Remarks

If the Dictionary<(Of <(TKey, TValue>)>) does not contain an element with the specified key, the Dictionary<(Of <(TKey, TValue>)>) remains unchanged. No exception is thrown.

This method approaches an O(1) operation.

Examples

The following code example shows how to remove a key/value pair from a dictionary using the Remove method.

This code example is part of a larger example provided for the Dictionary<(Of <(TKey, TValue>)>) class.

Visual Basic

' Use the Remove method to remove a key/value pair.
Console.WriteLine(vbLf + "Remove(""doc"")")
openWith.Remove("doc")

If Not openWith.ContainsKey("doc") Then
    Console.WriteLine("Key ""doc"" is not found.")
End If

// Use the Remove method to remove a key/value pair.
Console.WriteLine("\nRemove(\"doc\")");
openWith.Remove("doc");

if (!openWith.ContainsKey("doc"))
{
    Console.WriteLine("Key \"doc\" is not found.");
}

Visual C++

// Use the Remove method to remove a key/value pair.
Console::WriteLine("\nRemove(\"doc\")");
openWith->Remove("doc");

if (!openWith->ContainsKey("doc"))
{
    Console::WriteLine("Key \"doc\" is not found.");
}

Version Information

.NET Framework

Supported in: 4, 3.5, 3.0, 2.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Portable Class Library

Supported in: Portable Class Library

Platforms

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

Reference

Dictionary<(Of <(TKey, TValue>)>) Class

System.Collections.Generic Namespace

Add

IDictionary<(Of <(TKey, TValue>)>)..::.Remove