First(TSource) Method (IEnumerable(TSource))

Enumerable.First<'TSource> Method (IEnumerable<'TSource>)


Returns the first element of a sequence.

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

static member First<'TSource> : 
        source:IEnumerable<'TSource> -> 'TSource


Type: System.Collections.Generic.IEnumerable<'TSource>

The IEnumerable<'T> to return the first element of.

Return Value

Type: TSource

The first element in the specified sequence.

Type Parameters


The type of the elements of source.

Exception Condition

source is null.


The source sequence is empty.

The First<'TSource>(IEnumerable<'TSource>) method throws an exception if source contains no elements. To instead return a default value when the source sequence is empty, use the FirstOrDefault<'TSource> method.

The following code example demonstrates how to use First<'TSource>(IEnumerable<'TSource>) to return the first element of an array.

No code example is currently available or this language may not be supported.

Universal Windows Platform
Available since 4.5
.NET Framework
Available since 3.5
Portable Class Library
Supported in: portable .NET platforms
Available since 2.0
Windows Phone Silverlight
Available since 7.0
Windows Phone
Available since 8.1
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