3v4l.org

run code in 500+ PHP versions simultaneously
<?php $r = &$a[]; var_dump($a, $r); $r = 2; var_dump($a, $r);
Output for 8.1.0 - 8.1.34, 8.2.0 - 8.2.30, 8.3.0 - 8.3.30, 8.4.1 - 8.4.18, 8.5.0 - 8.5.3
array(1) { [0]=> &NULL } NULL array(1) { [0]=> &int(2) } int(2)
preferences:
70.56 ms | 982 KiB | 4 Q