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

Definition

Inverts the order of the elements in a sequence.

public:
generic <typename TSource>
[System::Runtime::CompilerServices::Extension]
 static System::Linq::IQueryable<TSource> ^ Reverse(System::Linq::IQueryable<TSource> ^ source);
public static System.Linq.IQueryable<TSource> Reverse<TSource> (this System.Linq.IQueryable<TSource> source);
static member Reverse : System.Linq.IQueryable<'Source> -> System.Linq.IQueryable<'Source>
<Extension()>
Public Function Reverse(Of TSource) (source As IQueryable(Of TSource)) As IQueryable(Of TSource)

Type Parameters

TSource

The type of the elements of source.

Parameters

source
IQueryable<TSource>

A sequence of values to reverse.

Returns

IQueryable<TSource>

An IQueryable<T> whose elements correspond to those of the input sequence in reverse order.

Exceptions

source is null.

Examples

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
*/
Dim appleLetters As New List(Of Char)(New Char() _
                                      {"a"c, "p"c, "p"c, "l"c, "e"c})

' Reverse the order of the characters in the collection.
Dim reversed As IQueryable(Of Char) = _
   appleLetters.AsQueryable().Reverse()

Dim output As New System.Text.StringBuilder
For Each chr As Char In reversed
    output.Append(chr & " ")
Next

' Display the output.
MsgBox(output.ToString())

' This code produces the following output:
'
' e l p p a

Remarks

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.

Applies to