3v4l.org

run code in 150+ php & hhvm versions
Bugs & Features
<?php $a = 'hello'; $$a = 'world'; echo $a . " " . ${$a};
based on aoG5u
Output for 4.3.0 - 5.6.28, hhvm-3.10.0 - 3.12.0, 7.0.0 - 7.1.0
hello world