Question

I am trying to validate year using Regex.test in javascript, but no able to figure out why its returning false.

var regEx = new RegExp("^(19|20)[\d]{2,2}$"); 

regEx.test(inputValue) returns false for input value 1981, 2007

Thanks

Answer 1

As you’re creating a RegExp object using a string expression, you need to double the backslashes so they escape properly. Also [\d]{2,2} can be simplified to \d\d:

var regEx = new RegExp("^(19|20)\\d\\d$");

Or better yet use a regex literal to avoid doubling backslashes:

var regEx = /^(19|20)\d\d$/;