3v4l.org

run code in 500+ PHP versions simultaneously
<?php $array = [false, false, false]; $key = 0; // $array[$key++] ||= true; $array[$key] = $array[$key] || true; ++$key; // $array[++$key] ||= true; ++$key; $array[$key] = $array[$key] || true; assert($array === [true, false, true]); var_dump($array);
Output for 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.34, 8.2.0 - 8.2.34, 8.3.0 - 8.3.35, 8.4.1 - 8.4.26, 8.5.0 - 8.5.11
array(3) { [0]=> bool(true) [1]=> bool(false) [2]=> bool(true) }

preferences:
29.77 ms | 1137 KiB | 7 Q