3v4l.org

run code in 200+ php & hhvm versions
Bugs & Features
<?php $a = ''; echo empty($a);
Output for 4.3.0 - 5.2.10, 5.2.12 - 5.4.45, 5.5.1 - 7.2.0
1
Output for 5.2.11, 5.5.0

Process exited with code 137.