XEnumerableSingleOrDefaultTSource Method (IEnumerableTSource, TSource)

Returns the only element of a sequence, or the specified default value if the sequence is empty; this method throws an exception if there is more than one element in the sequence.

Namespace: Linq.Extras
Assembly: Linq.Extras (in Linq.Extras.dll) Version: 5.0.0+96a4f4bfed64095342c5df107c1fe1fb95603ee5

Syntax

Copy

public static TSource SingleOrDefault<TSource>(
	this IEnumerable<TSource> source,
	TSource defaultValue
)

<ExtensionAttribute>
Public Shared Function SingleOrDefault(Of TSource) ( 
	source As IEnumerable(Of TSource),
	defaultValue As TSource
) As TSource

[<ExtensionAttribute>]
static member SingleOrDefault : 
        source : IEnumerable<'TSource> * 
        defaultValue : 'TSource -> 'TSource

Parameters

source: Type: System.Collections.GenericIEnumerableTSource
The sequence to return the single element of.
defaultValue: Type: TSource
The default value to return if the sequence is empty.

Type Parameters

TSource: The type of the elements of source.

Return Value

Type: TSource
The single element of the input sequence, or defaultValue if the sequence contains no elements.

Usage Note

In Visual Basic and C#, you can call this method as an instance method on any object of type IEnumerableTSource. When you use instance method syntax to call this method, omit the first parameter. For more information, see Extension Methods (Visual Basic) or Extension Methods (C# Programming Guide).

Reference

XEnumerable Class

SingleOrDefault Overload

Linq.Extras Namespace