3v4l.org

run code in 150+ php & hhvm versions
Bugs & Features
<?php $a .= "a"; $a .= "b"; $a .= "c"; var_dump($a);
Output for 5.0.4 - 5.6.28, 7.0.0 - 7.1.0
Notice: Undefined variable: a in /in/CQlLj on line 3 string(3) "abc"
Output for hhvm-3.10.0 - 3.12.0
string(3) "abc"
Output for 4.3.0 - 5.0.3
Notice: Undefined variable: a in /in/CQlLj on line 3 string(3) "abc"