Regular Expression for Password Strength Validation

Question

I have written a regular expression which could potentially be used for password strength validation:

^(?:([A-Z])*([a-z])*(\\d)*(\\W)*){8,12}$

Answer 1

You can do it by separating each group out and match them one by one, like this:

var level = 0;
var input = '';//user input goes here
switch(true){
    case /^(?:([A-Z])*){8,12}$/.test(input):
    level = 1;
    break;

    case /^(?:([A-Z])*([a-z])*){8,12}$/.test(input):
    level = 2;
    break;

    case /^(?:([A-Z])*([a-z])*(\d)*){8,12}$/.test(input):
    level = 3;
    break;

    case /^(?:([A-Z])*([a-z])*(\d)*(\W)*){8,12}$/.test(input):
    level = 4;
    break;
}

The level variable goes from 1 (the weakest) to 4 (the strongest).