javascript - JavaScript 中的自引用正则表达式

Question

我要认识

"Str","Int","[Str]","[Int]","[[Str]]",...

我以为我可以做类似的事情

(Str|Int|\[\1\])

其中 \1 self 引用组。我从形式语言理论知道正则表达式不能“计数”，因此不可能跟踪开始和结束 [ 和 ]。

我可能需要上下文无关语法，我该如何在 JS 中实现？

Answer 1

您可以将匹配组与 RegExp.prototype.exec() 结合使用.

var myString = "[[Str]]";
var myRegexp = /(\[*)Str(\]*)/g;
var match = myRegexp.exec(myString);
if (match[1] !== undefined && match[2] !== undefined && 
    match[1].length === match[2].length) {
   console.log('valid string');
}

来自 MDN:

If the match succeeds, the exec method returns an array and updates properties of the regular expression object. The returned array has the matched text as the first item, and then one item for each capturing parenthesis that matched containing the text that was captured.

If the match fails, the exec method returns null.

String.prototype.replace()可以类似地使用。