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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

Type Parameters


The type of the elements of source.


Type: System.Collections.Generic.IEnumerable(Of TSource)
A sequence in which to locate a 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.

Usage Note

In Visual Basic and C#, you can call this method as an instance method on any object of type IEnumerable(Of TSource). When you use instance method syntax to call this method, omit the first parameter. For more information, see Extension Methods (Visual Basic) or Extension Methods (C# Programming Guide).


source is Nothing.

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

.NET Framework

Supported in: 4, 3.5

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Portable Class Library

Supported in: Portable Class Library

Windows 7, Windows Vista SP1 or later, Windows XP SP3, 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.

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