/*

 *Author : @YunGaZeon

 *Date : 2017.08.09

 *param data : Data Array

 *param keys : Key level Array

 *return : Array

 */

 function findbykeys($data,$keys,$_index=0,&$_target_arr=[])

 {

     if($_index>(count($keys)-1))

         return $_target_arr;

     foreach($data as $k=>$v)

     {

         if($k===$keys[$_index])

         {

             if($_index==(count($keys)-1))

                 $_target_arr[]=$v;

             else

             {

                 if(is_array($v))

                     findbykeys($v,$keys,++$_index,$_target_arr);

             }

         }

         else

         {

             if(is_array($v))

                 findbykeys($v,$keys,$_index,$_target_arr);

         }

     }

     return $_target_arr;

 }

 $data=file_get_contents('https://club.jd.com/comment/productPageComments.action?callback=fetchJSON_comment&productId=5045080&score=0&sortType=5&page=1&pageSize=10&isShadowSku=0&rid=0&fold=1');

 $data=iconv('GBK', 'UTF-8//TRANSLIT//IGNORE', $data);

 preg_match('/^[^\(]+\(([\s\S]+)\);$/',$data,$data);

 $data=$data[1];

 $cm=json_decode($data,true);

 $keys=['comments','images','imgUrl'];

 var_dump(findbykeys($cm,$keys));