Enumerable.Distinct<'TSource> Method (IEnumerable<'TSource>)
Returns distinct elements from a sequence by using the default equality comparer to compare values.
Assembly: System.Core (in System.Core.dll)
static member Distinct<'TSource> : source:IEnumerable<'TSource> -> IEnumerable<'TSource>
The sequence to remove duplicate elements from.
Return ValueType: System.Collections.Generic.IEnumerable<'TSource>
An IEnumerable<'T> that contains distinct elements from the source sequence.
The type of the elements of source.
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 Default, to compare values.method returns an unordered sequence that contains no duplicate values. It uses the default equality comparer,
In Visual Basic query expression syntax, a Distinct clause translates to an invocation of.
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 useto return distinct elements from a sequence of integers.
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.
After you implement this interface, you can use a sequence of Product objects in the method, as shown in the following example.
Available since 8
Available since 3.5
Portable Class Library
Supported in: portable .NET platforms
Available since 2.0
Windows Phone Silverlight
Available since 7.0
Available since 8.1