3v4l.org

run code in 150+ php & hhvm versions
Bugs & Features
<?php $i = (int) $a = $b = array_fill(0, 100, 'bwoebi'); while($i++ < 1e3) { $b = array_merge($b, $a); }
Output for 7.0.12 - 7.1.0
Output for 5.3.7 - 5.4.28

Process exited with code 137.