Enumerable.Distinct(TSource) Method (IEnumerable(TSource), IEqualityComparer(TSource))
Returns distinct elements from a sequence by using a specified IEqualityComparer(T) to compare values.
Assemblies: System.Linq (in System.Linq.dll)
System.Core (in System.Core.dll)
static member Distinct : source:IEnumerable<'TSource> * comparer:IEqualityComparer<'TSource> -> IEnumerable<'TSource>
The type of the elements of source.
- Type: System.Collections.Generic.IEnumerable()
The sequence to remove duplicate elements from.
Return ValueType: System.Collections.Generic.IEnumerable()
An IEnumerable(T) that contains distinct elements from the source sequence.
Usage NoteIn Visual Basic and C#, you can call this method as an instance method on any object of type IEnumerable(). 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 a null reference (Nothing in Visual Basic).
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 method returns an unordered sequence that contains no duplicate values. If comparer is a null reference (Nothing in Visual Basic), the default equality comparer, Default, is used to compare values.
The following example shows how to implement an equality comparer that can be used in the Distinct method.
After you implement this comparer, you can use a sequence of Product objects in the Distinct method, as shown in the following example.
.NET FrameworkSupported in: 4.6, 4.5, 4, 3.5
.NET Framework Client ProfileSupported in: 4, 3.5 SP1
Portable Class LibrarySupported in: Portable Class Library
.NET for Windows Store appsSupported in: Windows 8
Supported in: Windows Phone 8.1
Supported in: Windows Phone Silverlight 8.1
Supported in: Windows Phone Silverlight 8
Windows Phone 8.1, Windows Phone 8, Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)