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

Enumerable.Contains<'TSource> Method (IEnumerable<'TSource>, 'TSource, IEqualityComparer<'TSource>)


Determines whether a sequence contains a specified element by using a specified IEqualityComparer<'T>.

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

static member Contains<'TSource> : 
        source:IEnumerable<'TSource> *
        value:'TSource *
        comparer:IEqualityComparer<'TSource> -> bool


Type: System.Collections.Generic.IEnumerable<'TSource>

A sequence in which to locate a value.

Type: TSource

The value to locate in the sequence.

Type: System.Collections.Generic.IEqualityComparer<'TSource>

An equality comparer to compare values.

Return Value

Type: System.Boolean

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

Type Parameters


The type of the elements of source.

Exception Condition

source is null.

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

If comparer is null, the default equality comparer, Default, is used to compare elements to the specified value.

The following example shows how to implement an equality comparer that can be used in the Contains<'TSource> method.

No code example is currently available or this language may not be supported.

After you implement this comparer, you can use a sequence of Product objects in the Contains<'TSource> method, as shown in the following example.

No code example is currently available or this language may not be supported.

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