3v4l.org

run code in 150+ php & hhvm versions
Bugs & Features
<?php $x = 0; $a = array(&$x); $b = $a; $x = 2; unset($x); $b[1]++; $b[0]++; echo $a[0], ' ', $b[0]; // 2 3
based on GebjV
Output for 5.3.0 - 5.6.28, 7.0.0 - 7.1.0
Notice: Undefined offset: 1 in /in/kjjYt on line 8 2 3
Output for hhvm-3.12.0
2 3
Output for hhvm-3.10.0

Process exited with code 153.
Output for 4.3.0 - 5.0.5, 5.1.1 - 5.2.17
Notice: Undefined offset: 1 in /in/kjjYt on line 8 2 3
Output for 5.1.0
Fatal error: fatal flex scanner internal error--end of buffer missed in /in/kjjYt on line 10
Process exited with code 255.