3v4l.org

run code in 300+ PHP versions simultaneously
<?php function x($n) { for($i = 1; $i <= $n; $i++) { if ($n % $i == 0 && $i != $n) { $factors[] = $i; echo "$i "; } } return (array_sum($factors) == $n) ? printf('Perfect') : printf('\[Imperfect\]'); } x(42);
Output for 4.3.0 - 4.3.11, 4.4.0 - 4.4.9, 5.0.0 - 5.0.5, 5.1.0 - 5.1.6, 5.2.0 - 5.2.17, 5.3.0 - 5.3.29, 5.4.0 - 5.4.45, 5.5.0 - 5.5.38, 5.6.0 - 5.6.40, 7.0.0 - 7.0.33, 7.1.0 - 7.1.33, 7.2.0 - 7.2.33, 7.3.0 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.28, 8.2.0 - 8.2.18, 8.3.0 - 8.3.7
1 2 3 6 7 14 21 \[Imperfect\]

preferences:
264.92 ms | 406 KiB | 460 Q