XEnumerableFirstOrDefaultTSource Method (IEnumerableTSource, FuncTSource, Boolean, TSource)

Returns the first element of the sequence that satisfies a condition or the specied default value if no such element is found.

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

Syntax

Copy

public static TSource FirstOrDefault<TSource>(
	this IEnumerable<TSource> source,
	Func<TSource, bool> predicate,
	TSource defaultValue
)

<ExtensionAttribute>
Public Shared Function FirstOrDefault(Of TSource) ( 
	source As IEnumerable(Of TSource),
	predicate As Func(Of TSource, Boolean),
	defaultValue As TSource
) As TSource

[<ExtensionAttribute>]
static member FirstOrDefault : 
        source : IEnumerable<'TSource> * 
        predicate : Func<'TSource, bool> * 
        defaultValue : 'TSource -> 'TSource

Parameters

source: Type: System.Collections.GenericIEnumerableTSource
The sequence to return an element from.
predicate: Type: SystemFuncTSource, Boolean
A function to test each element for a condition.
defaultValue: Type: TSource
The default value to return if no matching element is found.

Type Parameters

TSource: The type of the elements of source.

Return Value

Type: TSource
defaultValue if source is empty or if no element passes the test specified by predicate; otherwise, the first element in source that passes the test specified by predicate.

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

FirstOrDefault Overload

Linq.Extras Namespace