3v4l.org

run code in 300+ PHP versions simultaneously
<?php $a = [1,2,3,4,5,6,7,8,9]; foreach ($a as $key => &$value) { if ($key === 4) { unset($a[$key + 1]); // var_dump(key($a)); // break; } var_dump($key); } // var_dump(key($a));
Output for 5.4.1 - 5.4.45, 5.5.24 - 5.5.35, 5.6.7 - 5.6.28, 7.0.0 - 7.0.20, 7.1.0 - 7.1.10, 7.2.0 - 7.2.33, 7.3.16 - 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
int(0) int(1) int(2) int(3) int(4) int(6) int(7) int(8)
preferences:
181.55 ms | 404 KiB | 226 Q