无法读取未定义的node.js的属性“名称”

Question

运行节点服务器时，出现类型错误：无法读取未定义的属性“名称”。直到我console.log（“ tt3” + user_data.name），我才能console.log user_data.name。然后它只是说tt3undefined。

即使我能够console.log user_data.name，我仍然无法读取第一个um.getUser（）中未定义的属性“名称”；

我完全不知道问题是什么。

我相信我的功能也能正常运行。

当我console.log（user_data.name）时，它将打印名称

router.get('/users/game', function(req, res){
  var user_data = {
    name: req.query.player_name,
    password: req.query.password
  };

  console.log("does this exist"+user_data.name);
        if(user_data.name !=="" && user_data.password !== ""){ //if the password and username aren't blank
          //console.log(user_data.name);

                um.getUser(user_data.name, user_data.password, function(response){
                          var userinfo = response;
                          exports.logplayer = userinfo;
                  //console.log("tt" +user_data.name);
                  //console.log(exports.logplayer);
                        if(exports.logplayer == null){ //if the username and password dont exist
              //      console.log("tt2" +user_data.name);

                            um.getUsername(user_data.name,function(response){ //check to see if username exists
                      console.log("tt3" +user_data);
                                var userinfo = response;
                                exports.logplayer = userinfo;

                          if(exports.logplayer == null){ //if user name doesnt exist then create a new user
                              var newuser = new Player(user_data.name,0,0,0,0,0,0,user_data.password, "", "");
                              console.log(JSON.stringify(newuser) + "user couldn't be found in csv, so new user has been created");
                              um.updateUser(newuser,function(){ //this will update to csv
                              exports.logplayer = newuser;
                              res.status(200);
                              res.setHeader('Content-Type', 'text/html')
                              res.render('game', {user:exports.logplayer});
                                }); //updateUser
                            }
                          else{ //if username does exist, return index for them to input the correct password
                              var user_data = {
                              name:"",
                              password:"",
                              message:"The entered username exists but the entered password doesn't match it."
                              };

                              res.status(200);
                              res.setHeader('Content-Type', 'text/html')
                              res.render('index', {data:user_data});
                              console.log("wrong password");
                            }

                    });//       getusername
              }
          else{ //if the player already exists
            res.status(200);
            message = "Let's play!";
            res.setHeader('Content-Type', 'text/html')
            res.render('game', {user:exports.logplayer, message:message});
            console.log("rendering the game for an existing user:" + exports.logplayer.name);
          }
             });//getUser callback


      } //password/username isn't blank
      else{ // if password or username is blank
        var user_data = {
          name:"",
          password:"",
          message:"Please enter a username and password."
        };

        console.log(message);
        res.status(200);
        res.setHeader('Content-Type', 'text/html')
        res.render('index', {data:user_data});
      }


});//router.get('/users/game'