Fixed Length Random Number

[livethedead]

This isn't for anything practical, I'm just fiddling. Anyways, I'm wondering if there's anyway to make this more efficient since at higher lengths it could become really heavy. $l is length of the number.

 

	function fixed_random($l) {
	$number = "";
	do {
		$r = mt_rand(0, $l);
		$number .= $r;
	} while (strlen($number) < $l);
return $number;
}

[Jessica]

<?php
function fixed_random($digits) {
    $range_start = pow(10, $digits-1); // $digits=1, $range_start=0, 2:10, 3:100 ....
    $range_end = pow(10, $digits)-1; // $digits=1, $range_end=9, 2:99, 3: 999 ....
    $number = mt_rand($range_start, $range_end);
    return $number;
?>

 

Not tested, just my first thought.

[trq]

Quite easy. Say you want a random number that must have a length of 5.

 

Given that information, we know that it must be between 10000 and 99999, so:

 

mt_rand(10000, 99999);

 

Done.

[livethedead]

Hahaha oh dear /facepalm.