Enumerable.Last<(Of <(TSource>)>) Method (IEnumerable<(Of <(TSource>)>), Func<(Of <(TSource, Boolean>)>))
[ This article is for Windows Phone 8 developers. If you’re developing for Windows 10, see the latest documentation. ]
Returns the last element of a sequence that satisfies a specified condition.
Namespace: System.Linq
Assembly: System.Core (in System.Core.dll)
Syntax
<ExtensionAttribute> _
Public Shared Function Last(Of TSource) ( _
source As IEnumerable(Of TSource), _
predicate As Func(Of TSource, Boolean) _
) As TSource
public static TSource Last<TSource>(
this IEnumerable<TSource> source,
Func<TSource, bool> predicate
)
Type Parameters
- TSource
The type of the elements of source.
Parameters
- source
Type: System.Collections.Generic..::.IEnumerable<(Of <(TSource>)>)
An IEnumerable<(Of <(T>)>) to return an element from.
- predicate
Type: System..::.Func<(Of <(TSource, Boolean>)>)
A function to test each element for a condition.
Return Value
Type: TSource
The last element in the sequence that passes the test in the specified predicate function.
Usage Note
In Visual Basic and C#, you can call this method as an instance method on any object of type IEnumerable<(Of <(TSource>)>). When you use instance method syntax to call this method, omit the first parameter.
Exceptions
| Exception | Condition |
|---|---|
| ArgumentNullException | source or predicate is nullNothingnullptra null reference (Nothing in Visual Basic). |
| InvalidOperationException | No element satisfies the condition in predicate. -or- The source sequence is empty. |
Remarks
The Last<(Of <(TSource>)>)(IEnumerable<(Of <(TSource>)>), Func<(Of <(TSource, Boolean>)>)) method throws an exception if no matching element is found in source. To instead return a default value when no matching element is found, use the LastOrDefault method.
Examples
The following code example demonstrates how to use Last<(Of <(TSource>)>)(IEnumerable<(Of <(TSource>)>), Func<(Of <(TSource, Boolean>)>)) to return the last element of an array that satisfies a condition.
' Create an array of integers.
Dim numbers() As Integer = _
{9, 34, 65, 92, 87, 435, 3, 54, 83, 23, 87, 67, 12, 19}
' Get the last element in the array whose value is
' greater than 80.
Dim last As Integer = numbers.Last(Function(num) num > 80)
' Display the result.
outputBlock.Text &= last & vbCrLf
' This code produces the following output:
'
' 87
int[] numbers = { 9, 34, 65, 92, 87, 435, 3, 54,
83, 23, 87, 67, 12, 19 };
int last = numbers.Last(num => num > 80);
outputBlock.Text += last + "\n";
/*
This code produces the following output:
87
*/
Version Information
Windows Phone OS
Supported in: 8.1, 8.0, 7.1, 7.0
Platforms
Windows Phone