How can I format an integer to a specific length in javascript?

Question

I have a number in Javascript, that I know is less than 10000 and also non-negative. I want to display it as a four-digit number, with leading zeroes. Is there anything more e

Answer 1

This might help :

String.prototype.padLeft = function (length, character) { 
     return new Array(length - this.length + 1).join(character || '0') + this; 
}

var num = '12';

alert(num.padLeft(4, '0'));