3v4l.org

run code in 200+ php & hhvm versions
Bugs & Features
<?php $array = array(0 => 100, "color" => "red"); $keys = array_keys($array); print_r($keys["color"]); ?>
based on QnpgM
Output for 5.3.0 - 7.2.0
Notice: Undefined index: color in /in/d5URh on line 6
Output for 4.3.0 - 5.2.17
Notice: Undefined index: color in /in/d5URh on line 6