3v4l.org

run code in 200+ php & hhvm versions
Bugs & Features
<?php $data = array( 0, 1, 2 ); print_r ( array_keys($data) );
based on GbJ0M
Output for 4.3.0 - 7.2.0
Array ( [0] => 0 [1] => 1 [2] => 2 )