3v4l.org

run code in 150+ php & hhvm versions
Bugs & Features
<?php function _() { return 'foo'; } echo _();
Output for hhvm-3.10.0
foo
Output for 5.3.0 - 5.4.19
Fatal error: Cannot redeclare _() in /in/0Ug5l on line 6
Process exited with code 255.