RegExp.test returns false even though it should be true

Question

I'm trying to write this simple code into chrome live test and can't get it to return true.

var regExS = new RegExp("\d+x\d+");
regExS.test(" 240x120 (399.00)");

Even if I change the value to "240x120" it returns false. I've been googling and looking around and can't solve it.

Answer 1

If you are creating a RegExp from a string, the backslashes will need to be escaped ( "\\d" is the same as "d" ):

var regExS = new RegExp("\\d+x\\d+");

Alternatively you can use a regular expression literal:

var regExS = /\d+x\d+/;

Answer 2

The result of var regExS = new RegExp("\\d+x\\d+"); is /d+xd+/ .
You need to escape the backslashes when building a regex from a string:

var regExS = new RegExp("\\d+x\\d+");

or you could use a regex literal

var regExS = /\d+x\d+/;