Generate random string/characters in JavaScript

Question

I want a 5 character string composed of characters picked randomly from the set [a-zA-Z0-9].

What\'s the best way to do this with JavaScript?

Answer 1

Here are some easy one liners. Change new Array(5) to set the length.

Including 0-9a-z

new Array(5).join().replace(/(.|$)/g, function(){return ((Math.random()*36)|0).toString(36);})

Including 0-9a-zA-Z

new Array(5).join().replace(/(.|$)/g, function(){return ((Math.random()*36)|0).toString(36)[Math.random()<.5?"toString":"toUpperCase"]();});