Queryable.Reverse<TSource> Method

Inverts the order of the elements in a sequence.

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

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

Type Parameters

TSource

The type of the elements of source.

Parameters

source
Type: System.Linq.IQueryable<TSource>

A sequence of values to reverse.

Return Value

Type: System.Linq.IQueryable<TSource>
An IQueryable<T> whose elements correspond to those of the input sequence in reverse order.

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. For more information, see Extension Methods (Visual Basic) or Extension Methods (C# Programming Guide).

ExceptionCondition
ArgumentNullException

source is null.

The Reverse<TSource>(IQueryable<TSource>) method generates a MethodCallExpression that represents calling Reverse<TSource>(IQueryable<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 source parameter.

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

The following code example demonstrates how to use Reverse<TSource>(IQueryable<TSource>) to reverse the order of elements in an array.

            char[] apple = { 'a', 'p', 'p', 'l', 'e' };

            // Reverse the order of the characters in the collection.
            IQueryable<char> reversed = apple.AsQueryable().Reverse();

            foreach (char chr in reversed)
                Console.Write(chr + " ");
            Console.WriteLine();

            /*
                This code produces the following output:

                e l p p a
            */

.NET Framework

Supported in: 4.5.2, 4.5.1, 4.5, 4, 3.5

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Portable Class Library

Supported in: Portable Class Library

.NET for Windows Store apps

Supported in: Windows 8

.NET for Windows Phone apps

Supported in: Windows Phone 8.1, Windows Phone 8, Silverlight 8.1

Windows Phone 8.1, Windows Phone 8, Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

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