3v4l.org

run code in 300+ PHP versions simultaneously
<?php $tstart = microtime(true); $numberOfRandoms = 500; $uniques = array(); do { $uniques[mt_rand(10000, 99999)] = true; } while(count(array_keys($uniques)) < $numberOfRandoms); $uniques = array_keys($uniques); $elapsed = $tstart - $start; echo $elapsed . PHP_EOL;

preferences:
24.64 ms | 402 KiB | 5 Q