Enumerable.Last Enumerable.Last Enumerable.Last Enumerable.Last Method

定義

傳回序列的最後一個項目。Returns the last element of a sequence.

多載

Last<TSource>(IEnumerable<TSource>) Last<TSource>(IEnumerable<TSource>) Last<TSource>(IEnumerable<TSource>) Last<TSource>(IEnumerable<TSource>)

傳回序列的最後一個項目。Returns the last element of a sequence.

Last<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>) Last<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>) Last<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>) Last<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>)

傳回序列中符合指定之條件的最後一個元素。Returns the last element of a sequence that satisfies a specified condition.

Last<TSource>(IEnumerable<TSource>) Last<TSource>(IEnumerable<TSource>) Last<TSource>(IEnumerable<TSource>) Last<TSource>(IEnumerable<TSource>)

傳回序列的最後一個項目。Returns the last element of a sequence.

public:
generic <typename TSource>
[System::Runtime::CompilerServices::Extension]
 static TSource Last(System::Collections::Generic::IEnumerable<TSource> ^ source);
public static TSource Last<TSource> (this System.Collections.Generic.IEnumerable<TSource> source);
static member Last : seq<'Source> -> 'Source
<Extension()>
Public Function Last(Of TSource) (source As IEnumerable(Of TSource)) As TSource

類型參數

TSource

source 項目的類型。The type of the elements of source.

參數

source
IEnumerable<TSource>

要傳回最後一個項目的 IEnumerable<T>An IEnumerable<T> to return the last element of.

傳回

TSource TSource TSource TSource

位於來源序列中最後一個位置的值。The value at the last position in the source sequence.

例外狀況

範例

下列程式碼範例示範如何使用Last<TSource>(IEnumerable<TSource>)傳回陣列的最後一個元素。The following code example demonstrates how to use Last<TSource>(IEnumerable<TSource>) to return the last element of an array.

int[] numbers = { 9, 34, 65, 92, 87, 435, 3, 54, 
                    83, 23, 87, 67, 12, 19 };

int last = numbers.Last();

Console.WriteLine(last);

/*
 This code produces the following output:

 19
*/
' 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 item in the array.
Dim last As Integer = numbers.Last()

' Display the result.
MsgBox(last)

' This code produces the following output:
'
' 19

備註

Last<TSource>(IEnumerable<TSource>) 如果source沒有包含任何元素, 方法會擲回例外狀況。The Last<TSource>(IEnumerable<TSource>) method throws an exception if source contains no elements. 當來源序列是空的時, 若要改為傳回預設值LastOrDefault , 請使用方法。To instead return a default value when the source sequence is empty, use the LastOrDefault method.

Last<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>) Last<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>) Last<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>) Last<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>)

傳回序列中符合指定之條件的最後一個元素。Returns the last element of a sequence that satisfies a specified condition.

public:
generic <typename TSource>
[System::Runtime::CompilerServices::Extension]
 static TSource Last(System::Collections::Generic::IEnumerable<TSource> ^ source, Func<TSource, bool> ^ predicate);
public static TSource Last<TSource> (this System.Collections.Generic.IEnumerable<TSource> source, Func<TSource,bool> predicate);
static member Last : seq<'Source> * Func<'Source, bool> -> 'Source
<Extension()>
Public Function Last(Of TSource) (source As IEnumerable(Of TSource), predicate As Func(Of TSource, Boolean)) As TSource

類型參數

TSource

source 項目的類型。The type of the elements of source.

參數

source
IEnumerable<TSource>

傳回項目的 IEnumerable<T>An IEnumerable<T> to return an element from.

predicate
Func<TSource,Boolean>

用來測試每個項目是否符合條件的函式。A function to test each element for a condition.

傳回

TSource TSource TSource TSource

序列中通過指定之述詞函式所做測試的最後一個項目。The last element in the sequence that passes the test in the specified predicate function.

例外狀況

sourcepredicatenullsource or predicate is null.

沒有任何項目符合 predicate 的條件。No element satisfies the condition in predicate.

-或--or- 來源序列為空。The source sequence is empty.

範例

下列程式碼範例示範如何使用Last<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>)傳回陣列中符合條件的最後一個元素。The following code example demonstrates how to use Last<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>) to return the last element of an array that satisfies a condition.

int[] numbers = { 9, 34, 65, 92, 87, 435, 3, 54, 
                    83, 23, 87, 67, 12, 19 };

int last = numbers.Last(num => num > 80);

Console.WriteLine(last);

/*
 This code produces the following output:

 87
*/
' 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

備註

如果在中source找不到相符的元素,方法會擲回例外狀況。Last<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>)The Last<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>) method throws an exception if no matching element is found in source. 若要在找不到相符的元素時, 改為傳回預設LastOrDefault值, 請使用方法。To instead return a default value when no matching element is found, use the LastOrDefault method.

適用於