Enumerable.Last(Of TSource) Method (IEnumerable(Of TSource), Func(Of TSource, Boolean))
Returns the last element of a sequence that satisfies a specified condition.
Assembly: System.Core (in System.Core.dll)
'Declaration <ExtensionAttribute> _ Public Shared Function Last(Of TSource) ( _ source As IEnumerable(Of TSource), _ predicate As Func(Of TSource, Boolean) _ ) As TSource
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: TSourceThe 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. For more information, see Extension Methods (Visual Basic) or Extension Methods (C# Programming Guide).| Exception | Condition |
|---|---|
| ArgumentNullException | source or predicate is Nothing. |
| InvalidOperationException | No element satisfies the condition in predicate. -or- The source sequence is empty. |
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.
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.
MsgBox(last)
' This code produces the following output:
'
' 87
Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.