Question

I wanted to generate a random number 32 characters in length from a specified set of characters.

For example:

var chars = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXTZ";
var string_length = 32;

Which would then return a random number of length 32 using the specified characters.

Answer 1

var chars = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXTZ";
var string_length = 32;
var myrnd = [], pos;

// loop as long as string_length is > 0
while (string_length--) {
    // get a random number between 0 and chars.length - see e.g. http://www.shawnolson.net/a/789/make-javascript-mathrandom-useful.html
    pos = Math.floor(Math.random() * chars.length);
    // add the character from the base string to the array
    myrnd.push(chars.substr(pos, 1));
}

// join the array using '' as the separator, which gives us back a string
myrnd.join(''); // e.g "6DMIG9SP1KDEFB4JK5KWMNSI3UMQSSNT"