3v4l.org

run code in 200+ php & hhvm versions
Bugs & Features
<?php function foo(&$x) {return x;} $x = 42; unset(foo($x));
Output for 5.3.0 - 5.4.14
Fatal error: Can't use function return value in write context in /in/QXH0s on line 4
Process exited with code 255.