Enumerable.Intersect<(Of <(TSource>)>) Method (IEnumerable<(Of <(TSource>)>), IEnumerable<(Of <(TSource>)>), IEqualityComparer<(Of <(TSource>)>))

[ This article is for Windows Phone 8 developers. If you’re developing for Windows 10, see the latest documentation. ]

Produces the set intersection of two sequences by using the specified IEqualityComparer<(Of <(T>)>) to compare values.

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

Syntax

<ExtensionAttribute> _
Public Shared Function Intersect(Of TSource) ( _
    first As IEnumerable(Of TSource), _
    second As IEnumerable(Of TSource), _
    comparer As IEqualityComparer(Of TSource) _
) As IEnumerable(Of TSource)
public static IEnumerable<TSource> Intersect<TSource>(
    this IEnumerable<TSource> first,
    IEnumerable<TSource> second,
    IEqualityComparer<TSource> comparer
)

Type Parameters

  • TSource
    The type of the elements of the input sequences.

Parameters

Return Value

Type: System.Collections.Generic..::.IEnumerable<(Of <(TSource>)>)
A sequence that contains the elements that form the set intersection of two sequences.

Usage Note

In Visual Basic and C#, you can call this method as an instance method on any object of type IEnumerable<(Of <(TSource>)>). When you use instance method syntax to call this method, omit the first parameter.

Exceptions

Exception Condition
ArgumentNullException

first or second is nullNothingnullptra null reference (Nothing in Visual Basic).

Remarks

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 intersection of two sets A and B is defined as the set that contains all the elements of A that also appear in B, but no other elements.

When the object returned by this method is enumerated, Intersect enumerates first, collecting all distinct elements of that sequence. It then enumerates second, marking those elements that occur in both sequences. Finally, the marked elements are yielded in the order in which they were collected.

If comparer is nullNothingnullptra null reference (Nothing in Visual Basic), the default equality comparer, Default, is used to compare values.

Version Information

Windows Phone OS

Supported in: 8.1, 8.0, 7.1, 7.0

Platforms

Windows Phone

See Also

Reference

Enumerable Class

Intersect Overload

System.Linq Namespace