Queryable.Last<TSource> Method (IQueryable<TSource>)

Returns the last element in a sequence.

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

Syntax

'Declaration
<ExtensionAttribute> _
Public Shared Function Last(Of TSource) ( _
    source As IQueryable(Of TSource) _
) As TSource
public static TSource Last<TSource>(
    this IQueryable<TSource> source
)

Type Parameters

  • TSource
    The type of the elements of source.

Parameters

Return Value

Type: TSource
The value at the last position in source.

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

source is nulla null reference (Nothing in Visual Basic).

InvalidOperationException

The source sequence is empty.

Remarks

The Last<TSource>(IQueryable<TSource>) method generates a MethodCallExpression that represents calling Last<TSource>(IQueryable<TSource>) itself as a constructed generic method. It then passes the MethodCallExpression to the Execute<TResult>(Expression) method of the IQueryProvider represented by the Provider property of the source parameter.

The query behavior that occurs as a result of executing an expression tree that represents calling Last<TSource>(IQueryable<TSource>) depends on the implementation of the type of the source parameter. The expected behavior is that it returns the last element in source.

Examples

The following code example demonstrates how to use Last<TSource>(IQueryable<TSource>) to return the last element of an array.

      Dim numbers() As Integer = {9, 34, 65, 92, 87, 435, 3, 54, _
                          83, 23, 87, 67, 12, 19}

      Dim last As Integer = numbers.AsQueryable().Last()

      outputBlock.Text &= last & vbCrLf

      ' This code produces the following output:
      ' 19

         int[] numbers = { 9, 34, 65, 92, 87, 435, 3, 54, 
                                83, 23, 87, 67, 12, 19 };

         int last = numbers.AsQueryable().Last();

         outputBlock.Text += last + "\n";

         /*
             This code produces the following output:

             19
         */

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.