3v4l.org

run code in 200+ php & hhvm versions
Bugs & Features
<?php $val = 'abcd'; echo eval('return $'.val.';');
Output for 7.2.0
Warning: Use of undefined constant val - assumed 'val' (this will throw an Error in a future version of PHP) in /in/G6Loo on line 3 abcd
Output for 4.3.0 - 7.1.10
Notice: Use of undefined constant val - assumed 'val' in /in/G6Loo on line 3 abcd