3v4l.org

run code in 300+ PHP versions simultaneously
<?php $a = array(5 => true,4 => true,8 => true,6 => true); $b = array(5 => true,4 => true,6 => true,9 => true); print_r(array_diff_key($a,$b));

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28.72 ms | 402 KiB | 5 Q