3v4l.org

run code in 150+ php & hhvm versions
Bugs & Features
<?php $x = 0; var_dump($x); $a = array(&$x); var_dump($a); $b = $a; $x = 2; unset($x); $b[1]++; $b[0]++; echo $a[0], ' ', $b[0];
based on qNiGW
Output for 5.3.0 - 5.6.28, 7.0.0 - 7.1.0
int(0) array(1) { [0]=> &int(0) } Notice: Undefined offset: 1 in /in/bTfZZ on line 10 2 3
Output for hhvm-3.12.0
int(0) array(1) { [0]=> &int(0) } 2 3
Output for hhvm-3.10.0

Process exited with code 153.
Output for 4.3.0 - 5.2.17
int(0) array(1) { [0]=> &int(0) } Notice: Undefined offset: 1 in /in/bTfZZ on line 10 2 3