3v4l.org

run code in 150+ php & hhvm versions
Bugs & Features
<?php $string1 = 'check1'; $string2 = 'check2'; echo $string1 . $string3;
based on UGMlm
Output for 5.0.4 - 5.6.28, hhvm-3.10.0 - 3.12.0, 7.0.0 - 7.1.0
Notice: Undefined variable: string3 in /in/T6qPn on line 6 check1
Output for 4.3.0 - 5.0.3
Notice: Undefined variable: string3 in /in/T6qPn on line 6 check1