Question

我想得到两个字符串。该行的最后一个单词（在下面工作）然后是最后一个单词的所有内容，我想用正则表达式做这个。有人建议我使用 ^（。*？）\ b \ w + $ 作为模式并使用 $ 1 作为匹配（但我不知道如何在.NET中完成）

    Dim s As String = "   Now is the time for all good men to come to the aid of their country    "
    s = Regex.Replace(s, "^[ \s]+|[ \s]+$", "")  'Trim whitespace
    Dim lastword As String = Regex.Match(s, "\w*$", RegexOptions.None).ToString
    Debug.Print(lastword)

    Dim therest As String = Regex.Match(s,......)

Answer 1

我知道你写道“你想用正则表达式来做这件事”，但是因为没有正则表达式的解决方案这么容易，更具可读性和所以不太可能包含隐藏的错误，无论如何我都敢建议：

Dim s As String = "   Now is the time for all good men to come to the aid of their country    "
s = Trim(s)
Dim lastword = s.Split().Last()
Dim therest = Left(s, Len(s) - Len(lastword))

备选方案：

Dim therest = Left(s, s.LastIndexOf(" "))
Dim therest = s.Substring(0, s.LastIndexOf(" "))   ' Thanks to sixlettervariables
Dim therest = String.Join(" ", s.Split().Reverse().Skip(1).Reverse())   ' for LINQ fanatics ;-)

Answer 2

您的模式应该有效，而您正在寻找的是第一次捕获匹配集合：

Dim pattern As String = "^(.*?)\b\w+$"

' Use TrimEnd instead of regex replace (i.e. we don't nuke ant piles)
Dim match As Match = Regex.Match(input.TrimEnd(), pattern)

If match.Success Then
    ' It will be the 0th capture on the 1st group
    Dim allButTheLast As String = match.Groups(1).Captures(0)
    ' Group 0 is the entire input which matched
End If

除了一行的最后一个字，你怎么能匹配？

2 个答案: