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

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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)

Syntax

'Declaration
<ExtensionAttribute> _
Public Shared Function Intersect(Of TSource) ( _
    source1 As IQueryable(Of TSource), _
    source2 As IEnumerable(Of TSource) _
) As IQueryable(Of TSource)

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

Type Parameters

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

Parameters

  • source1
    Type: System.Linq.IQueryable<TSource>
    A sequence whose distinct elements that also appear in source2 are returned.

Return Value

Type: System.Linq.IQueryable<TSource>
A sequence that contains the set intersection of the two sequences.

Usage Note

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

Exceptions

Exception Condition
ArgumentNullException

source1 or source2 is nulla null reference (Nothing in Visual Basic).

Remarks

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.

Examples

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.

      Dim id1() As Integer = {44, 26, 92, 30, 71, 38}
      Dim id2() As Integer = {39, 59, 83, 47, 26, 4, 30}

      ' Get the numbers that occur in both arrays (id1 and id2).
      Dim both As IEnumerable(Of Integer) = id1.AsQueryable().Intersect(id2)

      Dim output As New System.Text.StringBuilder
      For Each id As Integer In both
         output.AppendLine(id)
      Next

      ' Display the output.
      outputBlock.Text &= output.ToString() & vbCrLf

      ' This code produces the following output:

      ' 26
      ' 30


         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)
            outputBlock.Text += id + "\n";

         /*
             This code produces the following output:

             26
             30
         */

Version Information

Silverlight

Supported in: 5, 4, 3

Silverlight for Windows Phone

Supported in: Windows Phone OS 7.1

Platforms

For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.