3v4l.org

run code in 200+ php & hhvm versions
Bugs & Features
<?php $foo = 'bar'; echo $foo[0]; echo $foo[-1];
Output for 7.1.0 - 7.2.0
br
Output for 5.3.21 - 7.0.20
b Notice: Uninitialized string offset: -1 in /in/0kM6Y on line 6