Online PHP editor | output for JQXUD

<?php $GET = [ "randomekey1" => "valueX", "randomkey2" => "valueY", "acceptedkey1" => "valueZ", "randomkey3" => "valueA", "acceptedkey2" => "valueB" ]; $whitelist = [ "acceptedkey1", "acceptedkey2", "acceptedkey3", ]; var_export( (bool)array_diff_key($GET, array_flip($whitelist)) ); echo "\n---\n"; $hasNotWhitelisted = false; $lookup = array_flip($whitelist); foreach ($GET as $key => $value) { if (isset($lookup[$key])) { $hasNotWhitelisted = true; break; } } var_export($hasNotWhitelisted); echo "\n---\n"; function hasNotWhitelisted($array, $whitelist): bool { $lookup = array_flip($whitelist); foreach ($array as $key => $value) { if (isset($lookup[$key])) { return true; } } return false; } var_export(hasNotWhitelisted($GET, $whitelist));