Question

I need to generate a string of numbers that are 20 digits long. Starting with 20 zeros ending with 20 nines. I can do this easily by running a normal rand(0,9) through a for loop.

for ($i = 0; $i < 20; $i++)
{
   $rng_salt .= rand(0,9);
}

But the loop is a lengthy process so to speak. I would like to try and figure out how to do this same thing with mt_rand(00000000000000000000, 99999999999999999999) or something similar. Preferably I’d like to do away with the loop and break it down to a single line if at all possible.

Answer 1

You can still have the whole loop in one line

for($i = 0, $rng_salt = ""; $i < 20; $i ++, $rng_salt .= mt_rand(0, 9));
var_dump($rng_salt);

You can also play around

$rng_salt = implode("",array_map(function($var){ return mt_rand(0, 9);}, range(0,19)));
var_dump($rng_salt);

What about doing some shuffle

$rng_salt = array_merge(range(0,9),range(0,9));
shuffle($rng_salt);
var_dump(implode("",$rng_salt));