3v4l.org

run code in 200+ php & hhvm versions
Bugs & Features
<?php $a = ' '; var_dump(substr($a, 1));
based on Xk4ck
Output for 7.0.0 - 7.3.0alpha1
string(0) ""
Output for 5.5.0 - 5.6.28
bool(false)