3v4l.org

run code in 200+ php & hhvm versions
Bugs & Features
<?php $foo[] = x; var_dump($foo);
Output for 7.2.0 - 7.2.6
Warning: Use of undefined constant x - assumed 'x' (this will throw an Error in a future version of PHP) in /in/Pi7U4 on line 2 array(1) { [0]=> string(1) "x" }
Output for 4.3.0 - 7.1.20
Notice: Use of undefined constant x - assumed 'x' in /in/Pi7U4 on line 2 array(1) { [0]=> string(1) "x" }