3v4l.org

run code in 300+ PHP versions simultaneously
<?php function perfect($n) { if ($n < 1) { echo "Number has to be Positive."; return false; } for($i = 1; $i <= $n; $i++) { if ($n % $i == 0) { $factors[] = $i; } } return ($n == array_sum($factors) / 2) ? true : false; } perfect(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 - 5.5.35, 5.6.0 - 5.6.28, 7.0.0 - 7.0.20, 7.1.0 - 7.1.33, 7.2.6 - 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 - 8.3.6

preferences:
235.89 ms | 406 KiB | 373 Q