3v4l.org

run code in 200+ php & hhvm versions
Bugs & Features
<?php $filter = 'ololo'; $k = 'fil.ter'; echo ${$k};
Output for 5.0.4 - 7.2.0
Notice: Undefined variable: fil.ter in /in/p3MuA on line 4
Output for 4.3.0 - 5.0.3
Notice: Undefined variable: fil.ter in /in/p3MuA on line 4