什么时候需要转义正则表达式字符集中的字符(在[]内)? [英] When do I need to escape characters within a regex character set (within [])?

问题描述

我在括号中逃脱的规则与我在括号外所做的规则不同吗?

Are the rules for what I escape in a bracket different for what I do outside of brackets?

例如我应该在括号内转义?吗?是/blah [^?]/还是/blah [^ \?]/

For example should I escape a ? inside a bracket? Is it /blah[^?]/ or /blah[^\?]/

括号的规则是否有所不同，还是我应该将两者都转义?

Are the rules for brackets different than not, or should I be escaping both the same?

推荐答案

唯一需要用方括号括起来的东西是一个右括号，如果不是首字母或结尾，则为负号；如果是首字母，则为一顶帽子.， 据我所知.还有反斜杠本身.

The only thing that needs to be escaped in brackets is a closing bracket, and a minus if it is not initial or final, and a hat if it is initial, AFAIK. And the backslash itself, obviously.

原因是，这些是方括号内唯一具有特殊意义的字符.右方括号括在方括号中，中间的减号表示范围，首字母否定方括号.其他所有内容都应按字面解释.反斜杠是转义符，因此您需要一个双反斜杠来匹配文字反斜杠.

The reason is, these are the only characters with a special significance inside the brackets. A closing bracket ends the brackets, a mid-string minus indicates a range, and an initial hat negates the bracket class. Everything else should be literally interpreted. The backslash is the escape character, so you need a double backslash to match a literal backslash.

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