3v4l.org

run code in 150+ php & hhvm versions
Bugs & Features
<?php $number = '9191919191'; $rest = substr($number, 0, 4); $rest2 = substr($number, 4 ,0); $f = $rest.'-'.$rest2; echo $f;
Output for 4.3.0 - 7.1.0
9191-