3v4l.org

run code in 200+ php & hhvm versions
Bugs & Features
<?php var_dump(serialize($f), serialize(null));
based on ErM7b
Output for 5.0.4 - 7.2.0
Notice: Undefined variable: f in /in/cY4ba on line 3 string(2) "N;" string(2) "N;"
Output for 4.3.0 - 5.0.3
Notice: Undefined variable: f in /in/cY4ba on line 3 string(2) "N;" string(2) "N;"