3v4l.org

run code in 150+ php & hhvm versions
Bugs & Features
<?php echo array_keys(array("1"=>0,"2"=>1));
Output for 5.4.18 - 5.6.28, hhvm-3.12.0, 7.0.0 - 7.1.0
Notice: Array to string conversion in /in/Ymqup on line 3 Array
Output for hhvm-3.10.0

Process exited with code 153.
Output for 5.4.0 - 5.4.17
Notice: Array to string conversion in /in/7iLBR on line 3 Array
Output for 4.3.0 - 5.3.29
Array