Last不是String（）的成员-VB.Net获取字符串的最后一个单词

Question

I'm trying to get the last word of a string. I split the string by spaces, and then get Last, but it's showing an error "Last is not a member of String()"

str = "This is a string of words"
str = currentPriceString.Split(" ").Last

What am I doing wrong?

note: I do have a System.Linq reference

Answer 1

You mentioned the assembly reference, but seems that you missed to specify the import at the top of the class/module that contains that unit of code you shown.

Imports System.Linq

If you also have the import, then probably what happens is that you are targeting a .NetFx version lower than v3.5, where doesn't not exist LINQ features, check your .Net Framework targetting and increase it up to v3.5 or greater.

Answer 2

Dim str As String = "This is a string of words"
Dim getLastWord As String = Mid(str, str.LastIndexOf(" ") + 2)

This will achieve getting any Characters past the last {space} in the String.

Answer 3

In order to use the IEnumerable.Last(Of TSource) extension method, your project must target .NET 3.5 or higher.

Please see the code example below:

Option Strict On
Option Explicit On

' The imports below are only required if the namespace(s)  
' have not been imported into your project's settings
Imports System.Linq ' Requires .NET 3.5 or higher
Imports Microsoft.VisualBasic ' This is required to use the Visual Basic functions like Mid(), InStr(), MsgBox(), etc...

Module Module1
    Sub Main()
        Dim str As String = "This is a string of words"
        Dim delim As Char = " "c
        Dim strArr As String() = str.Split(delim)
        Dim lastWord As String

        ' Requires the Microsoft Visual Basic namespace to be imported
        lastWord = Mid(str, InStrRev(str, delim) + 1I)
        lastWord = Mid(str, str.LastIndexOf(delim) + 2I)

        ' These are safe for .NET 2.0 and higher:
        lastWord = strArr(strArr.Length - 1I)
        lastWord = strArr(strArr.GetUpperBound(0I))

        ' These require .NET 3.5 and higher:
        lastWord = (From word As String In strArr Select word).Last
        lastWord = strArr.Last
        lastWord = strArr.ElementAt(strArr.GetUpperBound(0I))
    End Sub
End Module