Enumerable.ElementAt<TSource> Method

July 28, 2014

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 IEnumerable<TSource> source,
	int index
)

Type Parameters

TSource

The type of the elements of source.

Parameters

source
Type: System.Collections.Generic.IEnumerable<TSource>
An IEnumerable<T> to return an element from.
index
Type: System.Int32
The zero-based index of the element to retrieve.

Return Value

Type: TSource
The element at the specified position in the source sequence.

Usage Note

In Visual Basic and C#, you can call this method as an instance method on any object of type IEnumerable<TSource>. When you use instance method syntax to call this method, omit the first parameter.

ExceptionCondition
ArgumentNullException

source is null.

ArgumentOutOfRangeException

index is less than 0 or greater than or equal to the number of elements in source.

If the type of source implements IList<T>, that implementation is used to obtain the element at the specified index. Otherwise, this method obtains the specified element.

This method throws an exception if index is out of range. To instead return a default value when the specified index is out of range, use the ElementAtOrDefault<TSource> method.

The following code example demonstrates how to use ElementAt<TSource> to return an element at a specific position.


      string[] names =
             { "Hartono, Tommy", "Adams, Terry", "Andersen, Henriette Thaulow", 

                 "Hedlund, Magnus", "Ito, Shu" };
      Random random = new Random(DateTime.Now.Millisecond);

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

      outputBlock.Text += String.Format("The name chosen at random is '{0}'.", name) + "\n";

      /*
       This code produces the following sample output:

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



Windows Phone OS

Supported in: 8.1, 8.0, 7.1, 7.0

Windows Phone

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