3v4l.org

run code in 300+ PHP versions simultaneously
<?php $arr = [[1]=>[[100]], [2]=>]; $ref = &$arr[1]; $ref[] = [101]; var_dump($arr);
Output for 5.4.0 - 5.4.29
Parse error: syntax error, unexpected ']' in /in/SaJH3 on line 3
Process exited with code 255.
Output for 5.3.0 - 5.3.28
Parse error: syntax error, unexpected '[' in /in/SaJH3 on line 3
Process exited with code 255.
preferences:
196.51 ms | 1394 KiB | 66 Q