Contains(TSource) Method (IEnumerable(TSource), TSource)

Enumerable.Contains(Of TSource) Method (IEnumerable(Of TSource), TSource)

 

Determines whether a sequence contains a specified element by using the default equality comparer.

Namespace:   System.Linq
Assembly:  System.Core (in System.Core.dll)

<ExtensionAttribute>
Public Shared Function Contains(Of TSource) (
	source As IEnumerable(Of TSource),
	value As TSource
) As Boolean

Parameters

source
Type: System.Collections.Generic.IEnumerable(Of TSource)

A sequence in which to locate a value.

value
Type: TSource

The value to locate in the sequence.

Return Value

Type: System.Boolean

true if the source sequence contains an element that has the specified value; otherwise, false.

Type Parameters

TSource

The type of the elements of source.

Exception Condition
ArgumentNullException

source is null.

If the type of source implements ICollection(Of T), the Contains method in that implementation is invoked to obtain the result. Otherwise, this method determines whether source contains the specified element.

Enumeration is terminated as soon as a matching element is found.

Elements are compared to the specified value by using the default equality comparer, Default.

The following code example demonstrates how to use Contains(Of TSource)(IEnumerable(Of TSource), TSource) to determine whether an array contains a specific element.

' Create an array of strings.
Dim fruits() As String = {"apple", "banana", "mango", "orange", "passionfruit", "grape"}

' This is the string to search the array for.
Dim fruit As String = "mango"

' Determine if the array contains the specified string.
Dim hasMango As Boolean = fruits.Contains(fruit)

Dim text As String = IIf(hasMango, "does", "does not")

' Display the output.
MsgBox("The array " & text & " contain " & fruit)

' This code produces the following output:
'
' The array does contain mango

Universal Windows Platform
Available since 4.5
.NET Framework
Available since 3.5
Portable Class Library
Supported in: portable .NET platforms
Silverlight
Available since 2.0
Windows Phone Silverlight
Available since 7.0
Windows Phone
Available since 8.1
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