Generate random number again if it doesn't equal x - php

Question

I want to generate a number between 1 and 100, but I want it to keep regenerating that number until it equals 50, once it equals 50, then echo it out. How would I do this?
My Function:
function create() {
$production_line = mt_rand(0, 3);
$random1 = mt_rand(0, 9);
$random2 = mt_rand(0, 9);
$random3 = mt_rand(0, 9);
$random4 = mt_rand(0, 9);
$random5 = mt_rand(0, 9);
$random6 = mt_rand(0, 9);
$production_year = mt_rand(3, 4);
$week1 = 4;
$week2 = 8;
$factory1 = 4;
$factory2 = 8;
if ($production_line + $random1 + $random2 + $random3 + $random4 + $random5 + $random6 + $production_year + $week1 + $week2 + $factory1 + $factory2 == 55) {
return $production_line.$random1.$random2.$random3.$random4.$random5.$random6.$production_year.$week1.$week2.$factory1.$factory2;
}
}

Answer 1

Use a simple loop:
$i = 0;
while ($rand = mt_rand(0,100)) {
$i++;
if ($rand == 50) {
// found 50, so break out of the loop
break;
}
}
echo "It took $i iterations to find 50";
But that's a bit pointless, right? If you're just going to output 50 all the time, then why do you need to generate a random number? Just echo 50 instead. Also note that this could be a slow operation if the larger limit is a bigger number.

Answer 2

Generate and test all the random numbers inside a while loop.
function create() {
$week1 = 4;
$week2 = 8;
$factory1 = 4;
$factory2 = 8;
while (true) {
$production_line = mt_rand(0, 3);
$random1 = mt_rand(0, 9);
$random2 = mt_rand(0, 9);
$random3 = mt_rand(0, 9);
$random4 = mt_rand(0, 9);
$random5 = mt_rand(0, 9);
$random6 = mt_rand(0, 9);
$production_year = mt_rand(3, 4);
if ($production_line + $random1 + $random2 + $random3 + $random4 + $random5 + $random6 + $production_year + $week1 + $week2 + $factory1 + $factory2 == 55) {
return $production_line.$random1.$random2.$random3.$random4.$random5.$random6.$production_year.$week1.$week2.$factory1.$factory2;
}
}
}

Answer 3

I've rearranged bits of the code to make it more cohesive:
function create() {
do {
$arr = [
mt_rand(0, 3), // line
mt_rand(0, 9),
mt_rand(0, 9),
mt_rand(0, 9),
mt_rand(0, 9),
mt_rand(0, 9),
mt_rand(0, 9),
mt_rand(3, 4), // year
4, // weeks
8,
4, // factories
8,
];
} while (array_sum($arr) != 55);
return join('', $arr);
}

Answer 4

$number = 0;
$try = 0;
while ($number != 50) {
$try++;
$number = rand(1,100);
}
echo "found $number after $try cycles";