3v4l.org

run code in 150+ php & hhvm versions
Bugs & Features
<?php function foo(&$var) { echo ++$var . '<br>'; } $a=5; foo($a); $a+=4; foo($a);
based on HDrG4
Output for 4.3.0 - 5.6.28, hhvm-3.10.0 - 3.12.0, 7.0.0 - 7.1.0
6<br>11<br>