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Enumerable::Distinct<TSource> Method (IEnumerable<TSource>^)

 

Returns distinct elements from a sequence by using the default equality comparer to compare values.

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

public:
generic<typename TSource>
[ExtensionAttribute]
static IEnumerable<TSource>^ Distinct(
	IEnumerable<TSource>^ source
)

Parameters

source
Type: System.Collections.Generic::IEnumerable<TSource>^

The sequence to remove duplicate elements from.

Return Value

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

An IEnumerable<T> that contains distinct elements from the source sequence.

Type Parameters

TSource

The type of the elements of source.

Exception Condition
ArgumentNullException

source is null.

This method is implemented by using deferred execution. The immediate return value is an object that stores all the information that is required to perform the action. The query represented by this method is not executed until the object is enumerated either by calling its GetEnumerator method directly or by using foreach in Visual C# or For Each in Visual Basic.

The Distinct<TSource>(IEnumerable<TSource>^) method returns an unordered sequence that contains no duplicate values. It uses the default equality comparer, Default, to compare values.

In Visual Basic query expression syntax, a Distinct clause translates to an invocation of Distinct<TSource>.

The default equality comparer, Default, is used to compare values of the types that implement the IEquatable<T> generic interface. To compare a custom data type, you need to implement this interface and provide your own GetHashCode and Equals methods for the type.

For an example that uses IEqualityComparer<T>to define a custom comparer, see Distinct<TSource>(IEnumerable<TSource>^, IEqualityComparer<TSource>^).

The following code example demonstrates how to use Distinct<TSource>(IEnumerable<TSource>^) to return distinct elements from a sequence of integers.

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

If you want to return distinct elements from sequences of objects of some custom data type, you have to implement the IEquatable<T> generic interface in the class. The following code example shows how to implement this interface in a custom data type and provide GetHashCode and Equals methods.

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

After you implement this interface, you can use a sequence of Product objects in the Distinct<TSource>(IEnumerable<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
Silverlight
Available since 2.0
Windows Phone Silverlight
Available since 7.0
Windows Phone
Available since 8.1
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