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run code in 150+ php & hhvm versions
Bugs & Features
<?php $array = array(0 => 100, "color" => "red"); print_r(array_keys($array));
Output for 4.3.0 - 5.6.29, hhvm-3.10.0 - 3.13.2, 7.0.0 - 7.1.0
Array ( [0] => 0 [1] => color )