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run code in 150+ php & hhvm versions
Bugs & Features
<?php $test = array('1' => 'a', '2' => 'b'); echo array_keys($test);
Output for 5.4.0 - 7.1.0
Notice: Array to string conversion in /in/B0fY6 on line 3 Array
Output for 4.3.0 - 5.3.29
Array