3v4l.org

run code in 200+ php & hhvm versions
Bugs & Features
<?php $arr = ['$and'=> ['task.discriminator' => 'filippo', 'status.deleted' => 'asdf']]; $iterator = new RecursiveIteratorIterator(new RecursiveArrayIterator($arr)); $keys = array(); foreach ($iterator as $key => $value) { $keys[] = $key; } var_export($keys);
based on fX5Wo
Output for 5.6.0 - 5.6.30, hhvm-3.12.14 - 3.17.3, 7.0.0 - 7.1.7
array ( 0 => 'task.discriminator', 1 => 'status.deleted', )