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run code in 200+ php & hhvm versions
Bugs & Features
<?php $ha = array(); cats($ha['dne']); function cats($x = null) { $y = array_merge(array(''), $x); print_r($y); }
Output for 5.3.0 - 7.2.0
Notice: Undefined index: dne in /in/cuqcI on line 3 Warning: array_merge(): Argument #2 is not an array in /in/cuqcI on line 6
Output for 5.0.0 - 5.2.17
Notice: Undefined index: dne in /in/cuqcI on line 3 Warning: array_merge(): Argument #2 is not an array in /in/cuqcI on line 6
Output for 4.3.0 - 4.4.9
Notice: Undefined index: dne in /in/cuqcI on line 3 Array ( [0] => )