全面的 RegExp 删除 JavaScript 注释 [英] Comprehensive RegExp to remove JavaScript comments

问题描述

我需要使用单个正则表达式可靠地删除所有 JavaScript 注释.

I need to dependably remove all JavaScript comments with a single Regular Expression.

我搜索过 StackOverflow 和其他网站，但都没有考虑到交替引号、多行注释、字符串中的注释、正则表达式等.

I have searched StackOverflow, and other sites, but none take into account alternating quotes, multi-line comments, comments within strings, regular expressions, etc.

是否有任何正则表达式可以从中删除注释:

Is there any Regular expressions that can remove the comments from this:

var test = [
    "// Code",
    '// Code',
    "'// Code",
    '"// Code',
    //" Comment",
    //' Comment',
    /* Comment */
    // Comment /* Comment
    /* Comment
     Comment // */ "Code",
    "Code",
    "/* Code */",
    "/* Code",
    "Code */",
    '/* Code */',
    '/* Code',
    'Code */',
    /* Comment
    "Comment",
    Comment */ "Code",
    /Code\/*/,
    "Code */"
]

这是一个 jsbin 或 jsfiddle 来测试它.

Here's a jsbin or jsfiddle to test it.

推荐答案

我喜欢挑战:)

这是我的工作解决方案:

Here's my working solution:

/((["'])(?:\\[\s\S]|.)*?\2|\/(?![*\/])(?:\\.|\[(?:\\.|.)\]|.)*?\/)|\/\/.*?$|\/\*[\s\S]*?\*\//gm

将其替换为 $1.

在这里小提琴:http://jsfiddle.net/LucasTrz/DtGq8/6/

当然，正如无数次指出的那样，适当的解析器可能会更好，但仍然......

Of course, as it has been pointed out countless times, a proper parser would probably be better, but still...

注意:我在正则表达式字符串的小提琴中使用了正则表达式文字，过多的转义会破坏你的大脑.

NB: I used a regex literal in the fiddle insted of a regex string, too much escaping can destroy your brain.

((["'])(?:\\[\s\S]|.)*?\2|\/(?![*\/])(?:\\.|\[(?:\\.|.)\]|.)*?\/) <-- the part to keep
|\/\/.*?$                                                         <-- line comments
|\/\*[\s\S]*?\*\/                                                 <-- inline comments

要保留的部分

(["'])(?:\\[\s\S]|.)*?\2                   <-- strings
\/(?![*\/])(?:\\.|\[(?:\\.|.)\]|.)*?\/     <-- regex literals

字符串

    ["']              match a quote and capture it
    (?:\\[\s\S]|.)*?  match escaped characters or unescpaed characters, don't capture
    \2                match the same type of quote as the one that opened the string

正则表达式文字

    \/                          match a forward slash
    (?![*\/])                   ... not followed by a * or / (that would start a comment)
    (?:\\.|\[(?:\\.|.)\]|.)*?   match any sequence of escaped/unescaped text, or a regex character class
    \/                          ... until the closing slash

要删除的部分

|\/\/.*?$              <-- line comments
|\/\*[\s\S]*?\*\/      <-- inline comments

行注释

    \/\/         match two forward slashes
    .*?$         then everything until the end of the line

内嵌评论

    \/\*         match /*
    [\s\S]*?     then as few as possible of anything, see note below
    \*\/         match */

我不得不使用 [\s\S] 而不是 . 因为不幸的是 JavaScript 不支持正则表达式 s 修饰符(单行- 这个允许 . 匹配换行符)

I had to use [\s\S] instead of . because unfortunately JavaScript doesn't support the regex s modifier (singleline - this one allows . to match newlines as well)

此正则表达式适用于以下极端情况:

This regex will work in the following corner cases:

• 字符类中包含 / 的正则表达式模式:/[/]/
• 字符串文字中的转义换行符

而且只是为了乐趣...这是令人眼花缭乱的硬核版本:

And just for the fun of it... here's the eye-bleeding hardcore version:

/((["'])(?:\\[\s\S]|.)*?\2|(?:[^\w\s]|^)\s*\/(?![*\/])(?:\\.|\[(?:\\.|.)\]|.)*?\/(?=[gmiy]{0,4}\s*(?![*\/])(?:\W|$)))|\/\/.*?$|\/\*[\s\S]*?\*\//gm

这会添加以下扭曲的边缘情况(fiddle、regex101):

This adds the following twisted edge case (fiddle, regex101):

Code = /* Comment */ /Code regex/g  ; // Comment
Code = Code / Code /* Comment */ /g  ; // Comment    
Code = /Code regex/g /* Comment */  ; // Comment

这是高度启发式的代码，您可能不应该使用它(甚至比之前的正则表达式还要少)，而只是让这种极端情况发生.

This is highly heuristical code, you probably shouldn't use it (even less so than the previous regex) and just let that edge case blow.

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