在 Java 正则表达式中匹配“_”和“-”
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Matching '_' and '-' in java regexes
提问by Pablo Fernandez
I had this regex in javathat matched either an alphanumeric character or the tilde (~)
我在java中有这个正则表达式匹配字母数字字符或波浪号 (~)
^([a-z0-9])+|~$
^([a-z0-9])+|~$
Now I have to add also the characters -and _I've tried a few combinations, neither of which work, for example:
现在我还必须添加字符，-并且_我尝试了几种组合，但都不起作用，例如：
^([a-zA-Z0-9_-])+|~$^([a-zA-Z0-9]|-|_)+|~$
^([a-zA-Z0-9_-])+|~$^([a-zA-Z0-9]|-|_)+|~$
Sample input strings that must match:
必须匹配的示例输入字符串：
woZOQNVddd
woZOQNVdd
00000
00000
ncnW0mL14-
ncnW0mL14-
dEowBO_Eu7
dEowBO_Eu7
7MyG4XqFz-
7MyG4XqFz-
A8ft-y6hDu ~
A8ft-y6hDu ~
Any clues / suggestion?
任何线索/建议？
回答by cletus
-is a special character within square brackets. It indicates a range. If it's not at either end of the regex it needs to be escaped by putting a \before it.
-是方括号内的特殊字符。它表示一个范围。如果它不在正则表达式的任何一端，则需要通过\在它之前放置 a 来进行转义。
It's worth pointing out a shortcut: \wis equivalent to [0-9a-zA-Z_]so I think this is more readable:
值得指出一个快捷方式：\w相当于[0-9a-zA-Z_]所以我认为这更具可读性：
^([\w-]+|~$
回答by danben
You need to escape the -, like \-, since it is a special character (the range operator). _is ok.
您需要转义-, like \-，因为它是一个特殊字符（范围运算符）。 _没问题。
So ^([a-z0-9_\-])+|~$.
所以^([a-z0-9_\-])+|~$。
Edit: your last input String will not match because the regular expression you are using matches a string of alphanumeric characters (plus -and _) OR a tilde (because of the pipe). But not both. If you want to allow an optional tilde on the end, change to:
编辑：您的最后一个输入字符串将不匹配，因为您使用的正则表达式匹配一串字母数字字符（加号-和_）或波浪号（由于管道）。但不能两者兼而有之。如果要在末尾允许可选波浪号，请更改为：
^([a-z0-9_\-])+(~?)$
^([a-z0-9_\-])+(~?)$
回答by Bill the Lizard
If you put the -first, it won't be interpreted as the range indicator.
如果你把第-一个，它不会被解释为范围指示器。
^([-a-zA-Z0-9_])+|~$
This matches all of your examples except the last one using the following code:
这与使用以下代码的除最后一个之外的所有示例相匹配：
String str = "A8ft-y6hDu ~";
System.out.println("Result: " + str.matches("^([-a-zA-Z0-9_])+|~$"));
That last example won't match because it doesn't fit your description. The regex will match any combination of alphanumerics, -, and _, OR a ~ character.
最后一个示例不匹配，因为它不符合您的描述。正则表达式将匹配字母数字、- 和 _ 或 ~ 字符的任意组合。
