Question

我有一个关于选择JSON对象的部分并检查它们是否有值的问题我在PHP中从API加载JSON：

$json_url  ='http://api.url.com/api/gateway/call/1.4/getApp?appid=2631';
$ch = curl_init($json_url);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
$str = curl_exec($ch);
curl_close($ch);
$data = json_decode($str);

数据输出为：

object(stdClass)[1]
      public 'app' => 
        array
          0 => 
            object(stdClass)[2]
              public 'id' => string '2631' (length=4)
              public 'apptypeid' => string '3' (length=1)
              public 'organizerid' => string '913' (length=3)
              public 'accountId' => string '687' (length=3)
              public 'name' => string 'Meet in Liege' (length=13)
              public 'info' => string '' (length=0)
              public 'submit_description' => string '' (length=0)
              public 'category' => string '' (length=0)
              public 'app_icon' => string 'upload/appimages/2631/icon1024.png' (length=34)
              public 'homescreen' => string '' (length=0)
              public 'token' => string 'e6615c94a8b0fed28cdbec611669b19b' (length=32)
              public 'certificate' => string 'app2631' (length=7)
              public 'subdomain' => string 'mil13' (length=5)
              public 'cname' => string '' (length=0)
              public 'advancedFilter' => string '0' (length=1)
              public 'status' => string 'inactive' (length=8)
              public 'isdeleted' => string '0' (length=1)
              public 'creation' => string '2013-03-19 14:20:44' (length=19)
              public 'defaultlanguage' => string 'fr' (length=2)
              public 'visibleintapcrowd' => string '0' (length=1)
              public 'applestoreid' => string '0' (length=1)
              public 'address' => string '' (length=0)
              public 'lat' => string '0' (length=1)
              public 'lon' => string '0' (length=1)
              public 'telephone' => string '' (length=0)
              public 'email' => string '' (length=0)
              public 'website' => string '' (length=0)
              public 'contentmodule_css_phone' => string '' (length=0)
              public 'contentmodule_css_tablet' => string '' (length=0)
              public 'searchterms' => string '' (length=0)
              public 'fbid' => string '563672167017349' (length=15)
              public 'dropdb' => string '0000-00-00 00:00:00' (length=19)
              public 'bundle' => string 'com.tapcrowd.meetinliege2631' (length=28)
              public 'blankurl' => string '' (length=0)
              public 'header_html_phones' => string '' (length=0)
              public 'header_html_tablets' => string '' (length=0)
              public 'footer_html_phones' => string '' (length=0)
              public 'footer_html_tablets' => string '' (length=0)
              public 'themeid' => string '41' (length=2)
              public 'timestamp' => string '1368548676' (length=10)
              public 'subflavorid' => string '12' (length=2)
              public 'subflavortype' => string '3' (length=1)
              public 'subflavorpaidtype' => string '9999' (length=4)
              public 'show_external_ids_in_cms' => string '0' (length=1)
              public 'launcherview' => string '' (length=0)
              public 'responsive' => string '1' (length=1)
              public 'apptype' => string 'Event Flavor' (length=12)
              public 'channel' => string '1' (length=1)
              public 'aboutbuttonkey' => string 'About TapCrowd' (length=14)
              public 'aboutbuttonurl' => string 'http://m.tap.cr/about' (length=21)
      public 'appversion' => string '' (length=0)
      public 'events' => 
        array
          0 => 
            object(stdClass)[3]
              public 'id' => string '5004' (length=4)
              .......

现在我想检查一下应用程序数组的'info'，'app_icon'，'address'和'email'是否为空。
有谁知道我怎么做到这一点？这可能与JSON查询？我想用javascript进行操作！

Answer 1

你试过这个：

if(empty($data->app[0]->info)){
    // info empty
}
if(empty($data->app[0]->app_icon)){
    // app_icon empty
}
if(empty($data->app[0]->address)){
    // address empty
}
if(empty($data->app[0]->email)){
    // email empty
}

如果你将json传递给javascript然后使用（假设json被分配给一个名为data的变量）：

if(data.app[0].info.length === 0){
    // info empty
}

然后将info替换为您要检查的名称，重复其他人。

Answer 2

json_decode返回一个常规的PHP对象，所以应该很容易。如果我没有弄错的话，给定$data对象的结构，就可以了：

// Retrieve the app object from $data
$app = $data->app[0];

// Check whatever you want with the object elements
if empty($app->info) "info empty\n";
if empty($app->app_icon) "app_icon empty\n";
if empty($app->address) "address empty\n";
if empty($app->email) "email empty\n";

如果数组中有更多app个对象条目，您可以考虑使用foreach来处理它们。

Answer 3

你不能这样做：

if(trim($data->app[0]->info)=='' || is_null($data->app[0]->info)){
  echo "info empty";
}

if(trim($data->app[0]->app_icon)=='' || is_null($data->app[0]->app_icon)){
  echo "app_icon empty";
}

if(trim($data->app[0]->address)=='' || is_null($data->app[0]->address)){
  echo "address empty";
}

if(trim($data->app[0]->email)=='' || is_null($data->app[0]->email)){
  echo "email empty";
}

选择JSON的部分并检查值是否为空

3 个答案: