Online PHP editor | output for 5Rp9K

<?php $json = '{ "response": [ { "flight": { "number": "6204", "iata_number": "HV6204", "icao_number": "TRA6204" } }, { "flight": { "number": "7012", "iata_number": "TB7012", "icao_number": "JAF7012" } }, { "flight": { "number": "6652", "iata_number": "HV6652", "icao_number": "TRA6652" } }, { "flight": { "number": "1925", "iata_number": "W61925", "icao_number": "WZZ1925" } }, { "flight": { "number": "5075", "iata_number": "W65075", "icao_number": "WZZ5075" } }, { "flight": { "number": "4289", "iata_number": "W64289", "icao_number": "WZZ4289" } }, { "flight": { "number": "7861", "iata_number": "W67861", "icao_number": "WZZ7861" } }, { "flight": { "number": "3066", "iata_number": "FR3066", "icao_number": "RYR3066" } } ] }'; $jarr = json_decode($json, true); array_walk_recursive($jarr, function($v, $k) use (&$flights){ if($k == 'iata_number') $flights[] = $v; }); print_r($flights);