Question

I want to have a random serial created on my website everytime someone visits.

The format of the serial should be XXXXX-XXXXX-XXXXX-XXXXX.

X represents a random number or capital letter.

Unfortunately I have no idea how to do this. Could anybody please help me out?

So for example the random serial output could be: 3WT4A-NB34O-JU87P-B3UHS

Thanks a lot!

Answer 1

There are most certainly better ways of doing it, but this is the first that jumps to mind:

$chars = array(0,1,2,3,4,5,6,7,8,9,'A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z');
$serial = '';
$max = count($chars)-1;
for($i=0;$i<20;$i++){
    $serial .= (!($i % 5) && $i ? '-' : '').$chars[rand(0, $max)];
}

05/26/13 Edit: It’s advised to keep the Count function outside of the loop. The reason for this is that you don’t want to expend the extra clock cycles running this function through each iteration when you can simply run it once.