3v4l.org

run code in 200+ php & hhvm versions
Bugs & Features
<?php $foo = array(); echo (string)array_keys($foo);
based on AoXhs
Output for 5.6.0 - 5.6.30, hhvm-3.15.4, 7.0.0 - 7.2.6
Notice: Array to string conversion in /in/spe09 on line 6 Array