Contains Method (IKeyedCollection<TKey,TItem>)

Determines whether the collection contains an element with the specified key.

Syntax

Visual Basic
C#
C++/CLI

'Declaration
 
Function Contains( _
   ByVal key As TKey _
) As Boolean

'Usage
 
Dim instance As IKeyedCollection(Of TKey,TItem)
Dim key As TKey
Dim value As Boolean
 
value = instance.Contains(key)

bool Contains( 
   TKey key
)

bool Contains( 
   TKey^ key
)

Parameters

key: The key to locate in the IKeyedCollection<TKey,TItem>.
The value of this parameter cannot be null (Nothing in Visual Basic).

Return Value

true if the IKeyedCollection<TKey,TItem> contains an element with the specified key; otherwise, false.

Exceptions

Exception Description

Exception	Description
System.ArgumentNullException	A `null` reference (`Nothing` in Visual Basic) is passed to a method that does not accept it as a valid argument. This is a usage error, i.e. it will never occur (the exception will not be thrown) in a correctly written program. Your code should not catch this exception.

System.ArgumentNullException

A null reference (Nothing in Visual Basic) is passed to a method that does not accept it as a valid argument.

This is a usage error, i.e. it will never occur (the exception will not be thrown) in a correctly written program. Your code should not catch this exception.

Requirements

Target Platforms: .NET Framework: Windows 10 (selected versions), Windows 11 (selected versions), Windows Server 2016, Windows Server 2022; .NET: Linux, macOS, Microsoft Windows

Reference

IKeyedCollection<TKey,TItem> Interface
IKeyedCollection<TKey,TItem> Members
KeyedCollection.Contains(TKey) Method

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