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];
based on Uvf1I
Output for 5.3.0 - 5.6.28, 7.0.0 - 7.1.0
Notice: Undefined offset: 1 in /in/qcBob on line 8 1 1
Output for hhvm-3.12.0
1 1
Output for hhvm-3.10.0

Process exited with code 153.
Output for 4.3.0 - 5.2.17
Notice: Undefined offset: 1 in /in/qcBob on line 8 1 1