PHP获取json数组键位置

Question

如何获得数组results中键registration_id存在的所有位置?

  $json_raw = '{"multicast_id":6446899316497614986,
                     "success":5,
                     "failure":1,
                     "canonical_ids":3,
                     "results":[
                             {"registration_id":"APA91bEgLFvrc0lnXqX3C1euQohdHrv_wbxtGP86ezRzGWEVMQPpJjw1GMhGzfkI8Q34TU1KRts2j_-7CyU4ce6MlX5DB3umpXDGl-Ebmg53b44UKga79ee9Sal6gT_9rP3KIz9pDEUk2JVJsQmxiWXWoIfrYEAmFg",
                               "message_id":"0:1396175384218906%50b5570df9fd7ecd"
                             },
                             {"registration_id":"APA91bEgLFvrc0lnXqX3C1euQohdHrv_wbxtGP86ezRzGWEVMQPpJjw1GMhGzfkI8Q34TU1KRts2j_-7CyU4ce6MlX5DB3umpXDGl-Ebmg53b44UKga79ee9Sal6gT_9rP3KIz9pDEUk2JVJsQmxiWXWoIfrYEAmFg",
                              "message_id":"0:1396175384218155%50b5570df9fd7ecd"
                             },
                             {"registration_id":"APA91bEgLFvrc0lnXqX3C1euQohdHrv_wbxtGP86ezRzGWEVMQPpJjw1GMhGzfkI8Q34TU1KRts2j_-7CyU4ce6MlX5DB3umpXDGl-Ebmg53b44UKga79ee9Sal6gT_9rP3KIz9pDEUk2JVJsQmxiWXWoIfrYEAmFg",
                              "message_id":"0:1396175384219100%50b5570df9fd7ecd"
                             },
                             {"message_id":"0:1396175384218718%b91f4d1ff9fd7ecd"
                             },
                             {"message_id":"0:1396175384219927%50b5570df9fd7ecd"
                             },
                             {"error":"InvalidRegistration"
                             }]
                       }';

谢谢你的帮助!

Answer 1

您可以使用json_decode()。

$data = json_decode($json_raw, TRUE);
foreach ($data['results'] as $key=>$result) {
    if (array_key_exists('registration_id', $result)) {
       //use now via $data['results'][$key] or simply $result
    }
}

或者如果您只想保留registration_id存在的位置，请使用array_filter():

function registrationIdExists($result) {
    return array_key_exists('registration_id', $result);
}
$data = json_decode($json_raw, TRUE);
$data['results'] = array_filter($data['results'], "registrationIdExists");