3v4l.org

run code in 200+ php & hhvm versions
Bugs & Features
<?php $a0 = 'ab'; $a1 = 'a'; $a2 = 'b'; print ${$a1 + $a2};
based on N70lb
Output for 7.1.0 - 7.2.0
Warning: A non-numeric value encountered in /in/2rfhB on line 7 Warning: A non-numeric value encountered in /in/2rfhB on line 7 Notice: Undefined variable: 0 in /in/2rfhB on line 7
Output for 5.3.18 - 7.0.20
Notice: Undefined variable: 0 in /in/2rfhB on line 7