Javascript RegExp test fails

Question

I have problem with this regex:

(\[|\])[0-9]+,([0-9]+(\[|\])|inf\])\s?.*

Debuggex Demo

When I try to do code:

var rangeRegex = new RegExp("(\[|\])[0-9]+,([0-9]+(\[|\])|inf\])\s?.*");
console.log(rangeRegex.test("]1,inf] Test Expression"));

I always get false. Why?

Answer 1

When you use the RegExp construct, you need to double escape with your backslashes:

var rangeRegex = new RegExp("(\\[|\\])[0-9]+,([0-9]+(\\[|\\])|inf\\])\\s?.*");

Or use a literal one::

var rangeRegex = /(\[|\])[0-9]+,([0-9]+(\[|\])|inf\])\s?.*/;