Javascript RegEx不起作用 [英] Javascript RegEx Not Working

问题描述

我有以下javascript代码：

I have the following javascript code:

    function checkLegalYear() {
        var val = "02/2010"; 

        if (val != '') {
           var regEx = new RegExp("^(0[1-9]|1[0-2])/\d{4}$", "g");

            if (regEx.test(val)) {
               //do something
            }
            else {
               //do something
            }
        }
    }

但是，对于任何值，我的regEx测试总是返回false我通过了（02/2010）。我的代码中有什么问题吗？我已经在网上尝试了各种javascript编辑器上的代码，并且工作正常。

However, my regEx test always returns false for any value I pass (02/2010). Is there something wrong in my code? I've tried this code on various javascript editors online and it works fine.

推荐答案

因为你正在创建你的正则表达式一个字符串，你必须加倍你的反斜杠：

Because you're creating your regular expression from a string, you have to double-up your backslashes:

var regEx = new RegExp("^(0[1-9]|1[0-2])/\\d{4}$", "g");

这里没有理由不使用正则表达式语法：

There's really no reason here not to use regular expression syntax instead:

var regEx = /^(0[1-9]|1[0-2])\/\d{4}$/g;

edit —我还注意到有一个嵌入的/字符，如果你使用正则表达式语法，必须引用它。

edit — I also notice that there's an embedded "/" character, which has to be quoted if you use regex syntax.

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