如何在JavaScript中将输入括号与正则表达式匹配？ [英] How to match a input parenthesis with regular expression in JavaScript?

问题描述

我不知道将输入括号与JavaScript匹配。

I have no idea on matching the input parenthesis with JavaScript.

输入字符串示例：

(pen)
((pen) and orange)

如果输入字符串如下所示，它应该返回false：

it should return false if the input string is like the following:

(pen
pen)
(pen) and orange)
((pen and orange )
((pen) and orange 
)(pen and orange )(
(pen and )orange() 

推荐答案

在没有任何组的情况下更换每一组left paren - some chars - right paren。如果结果字符串包含一个括号，则parens不平衡。

replace every group of "left paren - some chars - right paren" with nothing, until there is no more groups. If the resulting string contains a parenthesis, the parens were not balanced.

balancedParens = function(str) {
    var q;   
    do {
      q = str;
      str = str.replace(/\([^()]*\)/g, '');
    } while(q != str);
    return !str.match(/[()]/);
}

    a = "foo ((and) bar and (baz) quux) and (blah)";
    b = "(dddddd()";

alert(balancedParens(a))
alert(balancedParens(b))

http://jsfiddle.net/gvGGT/

在javascript中无法将平衡字符串与单个正则表达式匹配，因为JS方言不支持递归表达式。

It's not possible to match a balanced string with a single regexp in javascript, because JS dialect doesn't support recursive expressions.

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