3v4l.org

run code in 150+ php & hhvm versions
Bugs & Features
<?php $foo = "test"; echo $${"foo"};
based on 7B0sq
Output for 5.0.4 - 7.1.0
Notice: Undefined variable: test in /in/GZIL6 on line 4
Output for 4.3.0 - 5.0.3
Notice: Undefined variable: test in /in/GZIL6 on line 4