3v4l.org

run code in 150+ php & hhvm versions
Bugs & Features
<?php $a = 'cdi'; $$a = 'world'; echo "$a $hello"; ?>
Output for 5.0.4 - 5.6.28, hhvm-3.10.0 - 3.12.0, 7.0.0 - 7.1.0
Notice: Undefined variable: hello in /in/R2l5r on line 4 cdi
Output for 4.3.0 - 5.0.3
Notice: Undefined variable: hello in /in/R2l5r on line 4 cdi