Queryable.ElementAt<TSource> Method (IQueryable<TSource>, Int32)


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Returns the element at a specified index in a sequence.

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

public static TSource ElementAt<TSource>(
	this IQueryable<TSource> source,
	int index


Type: System.Linq.IQueryable<TSource>

An IQueryable<T> to return an element from.

Type: System.Int32

The zero-based index of the element to retrieve.

Return Value

Type: TSource

The element at the specified position in source.

Type Parameters


The type of the elements of source.

Exception Condition

source is null.


index is less than zero.

The ElementAt<TSource>(IQueryable<TSource>, Int32) method generates a MethodCallExpression that represents calling ElementAt<TSource>(IQueryable<TSource>, Int32) 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 ElementAt<TSource>(IQueryable<TSource>, Int32) depends on the implementation of the type of the source parameter. The expected behavior is that it returns the item at position index in source.

The following code example demonstrates how to use ElementAt<TSource>(IQueryable<TSource>, Int32) to return an element at a specific position in a sequence.

string[] names = { "Hartono, Tommy", "Adams, Terry", 
                   "Andersen, Henriette Thaulow", 
                   "Hedlund, Magnus", "Ito, Shu" };

Random random = new Random(DateTime.Now.Millisecond);

string name =
    names.AsQueryable().ElementAt(random.Next(0, names.Length));

Console.WriteLine("The name chosen at random is '{0}'.", name);

    This code produces the following sample output.
    Yours may be different due to the use of Random.

    The name chosen at random is 'Ito, Shu'.

Universal Windows Platform
Available since 8
.NET Framework
Available since 3.5
Portable Class Library
Supported in: portable .NET platforms
Available since 2.0
Windows Phone Silverlight
Available since 7.1
Windows Phone
Available since 8.1
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