Intersect(TSource) Method (IQueryable(TSource), IEnumerable(TSource))

Queryable.Intersect<TSource> Method (IQueryable<TSource>, IEnumerable<TSource>)


Produces the set intersection of two sequences by using the default equality comparer to compare values.

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

public static IQueryable<TSource> Intersect<TSource>(
	this IQueryable<TSource> source1,
	IEnumerable<TSource> source2


Type: System.Linq.IQueryable<TSource>

A sequence whose distinct elements that also appear in source2 are returned.

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

A sequence whose distinct elements that also appear in the first sequence are returned.

Return Value

Type: System.Linq.IQueryable<TSource>

A sequence that contains the set intersection of the two sequences.

Type Parameters


The type of the elements of the input sequences.

Exception Condition

source1 or source2 is null.

The Intersect<TSource>(IQueryable<TSource>, IEnumerable<TSource>) method generates a MethodCallExpression that represents calling Intersect<TSource>(IQueryable<TSource>, IEnumerable<TSource>) itself as a constructed generic method. It then passes the MethodCallExpression to the CreateQuery<TElement>(Expression) method of the IQueryProvider represented by the Provider property of the source1 parameter.

The query behavior that occurs as a result of executing an expression tree that represents calling Intersect<TSource>(IQueryable<TSource>, IEnumerable<TSource>) depends on the implementation of the type of the source1 parameter. The expected behavior is that all the elements in source1 that are also in source2 are returned.

The following code example demonstrates how to use Intersect<TSource>(IQueryable<TSource>, IEnumerable<TSource>) to return the elements that appear in each of two sequences.

int[] id1 = { 44, 26, 92, 30, 71, 38 };
int[] id2 = { 39, 59, 83, 47, 26, 4, 30 };

// Get the numbers that occur in both arrays (id1 and id2).
IEnumerable<int> both = id1.AsQueryable().Intersect(id2);

foreach (int id in both)

    This code produces the following output:


Universal Windows Platform
Available since 4.5
.NET Framework
Available since 3.5
Portable Class Library
Supported in: portable .NET platforms
Available since 2.0
Windows Phone Silverlight
Available since 7.1
Windows Phone
Available since 8.1
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