在Java正则表达式中的字符类中使用方括号 [英] Using square brackets inside character class in Java regex

问题描述

下面是我为替换字符串中的特殊字符&!)(}{][^"~*?:;\+-而编写的正则表达式，但是以某种方式无法替换[& ]，因为它充当正则表达式的开始和结束.我该怎么办?

Below is the regex I have written to replace the special chars &!)(}{][^"~*?:;\+- from a string, but somehow it is not able to replace [ & ] from it as it acts as beginning and closing of regex. How can I do that?

System.out.println(" &!)(}{][^\"~*?:;\\+-".replaceAll("[| |&|!|)|(|}|{|^|\"|~|*|?|:|;|\\\\|+|-]", "_"));
}

现在的输出:_______][__________

推荐答案

您只需要在Java正则表达式的字符类中转义[和]即可.

You just need to escape the [ and ] inside a character class in a Java regex.

此外，您无需在字符类中将|作为替换符号，因为它被视为文字|.

Also, you do not need to put | as alternation symbol in the character class as it is treated as a literal |.

System.out.println(" &!)(}{][^\"~*?:;\\+-".replaceAll("[\\]\\[ &!)(}{^\"~*?:;\\\\+-]", "_"));
// => ___________________

请参见 Java演示

&dagger ;: _{请注意，在PCRE/Python/.NET，POSIX中，如果将方括号放在正确的位置，则不必在字符类中转义方括号:[]ab[].在JavaScript中，您始终必须转义]:/[^\]abc[]/.在Java和ICU正则表达式中，必须始终在字符类内同时转义[和]. – WiktorStribiżew17年1月10日在12:39}

†: _{Note that in PCRE/Python/.NET, POSIX, you do not have to escape square brackets in the character class if you put them at the right places: []ab[]. In JavaScript, you always have to escape ]: /[^\]abc[]/. In Java and ICU regexps, you must always escape both [ and ] inside the character class. – Wiktor Stribiżew Jan 10 '17 at 12:39}

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