3v4l.org

run code in 200+ php & hhvm versions
Bugs & Features
<?php $function = "function a() { echo 'Hi!'; }"; echo ${$function};
based on 3DKUE
Output for 5.0.4 - 7.2.0
Notice: Undefined variable: function a() { echo 'Hi!'; } in /in/dGt8A on line 3
Output for 4.3.0 - 5.0.3
Notice: Undefined variable: function a() { echo 'Hi!'; } in /in/dGt8A on line 3