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

July 28, 2014

Returns the last element in a sequence.

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

public static TSource Last<TSource>(
	this IQueryable<TSource> source
)

Type Parameters

TSource

The type of the elements of source.

Parameters

source
Type: System.Linq.IQueryable<TSource>
An IQueryable<T> to return the last element of.

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.

ExceptionCondition
ArgumentNullException

source is null.

InvalidOperationException

The source sequence is empty.

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.

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


         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
         */



Windows Phone OS

Supported in: 8.1, 8.0, 7.1

Windows Phone

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