3v4l.org

run code in 300+ PHP versions simultaneously
<?php function sub(&$data){} $data = array(); sub($data['nested']); echo serialize(array($data,$data));
Output for 5.6.0 - 5.6.24, 7.0.8 - 7.0.20, 7.1.0 - 7.1.20, 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 - 8.1.34, 8.2.0 - 8.2.30, 8.3.0 - 8.3.30, 8.4.1 - 8.4.18, 8.5.0 - 8.5.3
a:2:{i:0;a:1:{s:6:"nested";N;}i:1;a:1:{s:6:"nested";N;}}
Output for 7.0.0 - 7.0.7
a:2:{i:0;a:1:{s:6:"nested";N;}i:1;a:1:{s:6:"nested";R:3;}}
preferences:
113.77 ms | 1488 KiB | 4 Q