正则表达式范围中的转义点

这两种 regex 的作用方式相同:

var str = "43gf\\..--.65";


console.log(str.replace(/[^\d.-]/g, ""));
console.log(str.replace(/[^\d\.-]/g, ""));

在第一个正则表达式中，我不转义点(.) ，而在第二个正则表达式中，我转义点(\.)。

有什么不同? 为什么结果是一样的？

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最佳答案

Because the dot is inside character class (square brackets []).

Take a look at http://www.regular-expressions.info/reference.html, it says (under char class section):

Any character except ^-]\ add that character to the possible matches for the character class.

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The dot operator . does not need to be escaped inside of a character class [].

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Remember that the dot is not a metacharacter inside a character class, so we do not need to escape it with a backslash.

So I guess the escaping of it is unnecessary...

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If you using JavaScript to test your Regex, try \\. instead of \..

It acts on the same way because JS remove first backslash.