如何在Parse中获取对象字段

Question

以下是我对特定用户的查询：

  var query = new Parse.Query("User");

  query.get(userId, {
    success: function(user) {
      if (user === undefined){
        response.success("No such user with this ID: " + userId)
      }else{
        response.success("successfull " + user.get('authData')); //   authData is undefined whereas name, minAge and other primitive types are working fine
      }
    },

    error: function() {
      response.error("user lookup failed");
    }
  });

user.get('authData')正在返回undefined，但其他原始类型字段（如姓名和年龄）工作正常。

我认为这是因为authData是对象

我如何访问它？