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Enumerable.Contains<TSource> Method (IEnumerable<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)

public static bool Contains<TSource>(
	this IEnumerable<TSource> source,
	TSource value
)

Type Parameters

TSource

The type of the elements of source.

Parameters

source
Type: System.Collections.Generic.IEnumerable<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.

Usage Note

In Visual Basic and C#, you can call this method as an instance method on any object of type IEnumerable<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).

ExceptionCondition
ArgumentNullException

source is null.

If the type of source implements ICollection<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<TSource>(IEnumerable<TSource>, TSource) to determine whether an array contains a specific element.

            string[] fruits = { "apple", "banana", "mango", "orange", "passionfruit", "grape" };

            string fruit = "mango";

            bool hasMango = fruits.Contains(fruit);

            Console.WriteLine(
                "The array {0} contain '{1}'.",
                hasMango ? "does" : "does not",
                fruit);

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

.NET Framework

Supported in: 4.6, 4.5, 4, 3.5

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

XNA Framework

Supported in: 3.0

Portable Class Library

Supported in: Portable Class Library

Supported in: Windows Phone 8.1

Supported in: Windows Phone Silverlight 8.1

Supported in: Windows Phone Silverlight 8
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