Enumerable.ElementAt<TSource>(IEnumerable<TSource>, Int32) Method
Definition
Returns the element at a specified index in a sequence.
public:
generic <typename TSource>
[System::Runtime::CompilerServices::Extension]
static TSource ElementAt(System::Collections::Generic::IEnumerable<TSource> ^ source, int index);
public static TSource ElementAt<TSource> (this System.Collections.Generic.IEnumerable<TSource> source, int index);
static member ElementAt : seq<'Source> * int -> 'Source
<Extension()>
Public Function ElementAt(Of TSource) (source As IEnumerable(Of TSource), index As Integer) As TSource
Type Parameters
- TSource
The type of the elements of source
.
Parameters
- source
- IEnumerable<TSource>
An IEnumerable<T> to return an element from.
- index
- Int32
The zero-based index of the element to retrieve.
Returns
- TSource
The element at the specified position in the source sequence.
Exceptions
source
is null
.
index
is less than 0 or greater than or equal to the number of elements in source
.
Examples
The following code example demonstrates how to use ElementAt 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));
Console.WriteLine("The name chosen at random is '{0}'.", name);
/*
This code produces the following sample output:
The name chosen at random is 'Ito, Shu'.
*/
' Create an array of strings.
Dim names() As String =
{"Hartono, Tommy", "Adams, Terry", "Andersen, Henriette Thaulow", "Hedlund, Magnus", "Ito, Shu"}
Dim random As Random = New Random(DateTime.Now.Millisecond)
' Get a string at a random index within the array.
Dim name As String = names.ElementAt(random.Next(0, names.Length))
' Display the output.
Console.WriteLine($"The name chosen at random is {name}")
' This code produces the following output:
'
' The name chosen at random is Ito, Shu
Remarks
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 method.