Online PHP editor | refs for mLogS

<?php $list1 = [ [ "first_name" => "Fatima", "last_name" => "A.", "country" => "Algeria", "continent" => "Africa", "age" => 25, "language" => "JavaScript" ], [ "first_name" => "Agustin", "last_name" => "M.", "country" => "Chile", "continent" => "Americas", "age" => 37, "language" => "C" ], [ "first_name" => "Jing", "last_name" => "X", "country" => "China", "continent" => "Asia", "age" => 39, "language" => "Ruby" ], [ "first_name" => "Laia", "last_name" => "P.", "country" => "Andorra", "continent" => "Europe", "age" => 55, "language" => "Ruby" ], [ "first_name" => "Oliver", "last_name" => "Q.", "country" => "Australia", "continent" => "Oceania", "age" => 65, "language" => "PHP" ] ]; var_dump(!array_diff(['Africa', 'Americas', 'Asia', 'Europe', 'Oceania'], array_unique(array_column($list1, 'continent'))));