3v4l.org

run code in 300+ PHP versions simultaneously
<?php $a = []; for($i=0; $i<100; $i++){ for($z=0; $z<$i; $z++){ $a[$i][$z] = ($z - $i); } }
Output for 5.5.0 - 5.5.35, 5.6.0 - 5.6.28, 7.0.0 - 7.0.20, 7.1.0 - 7.1.33, 7.2.0 - 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 - 8.3.6
preferences:
233.41 ms | 404 KiB | 258 Q