Javascript 无法调用未定义的方法push（在已定义时）

我正在使用Node.js和mongoose为一个应用程序创建一个后端，在这里用户可以彼此成为朋友

模式

请求

控制台

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为什么数组在模式中定义时显示为已定义，而我正在检索正确的用户？感谢您的帮助

看起来您的guy对象实际上是一个JSON字符串，而不是一个JSON对象。尝试对其运行JSON解析

exports.addfriend = function(reg_id,friend,callback) {

  user.find({reg_id:reg_id},function(err,guy){   
    guy = JSON.parse(guy); //ADD THIS
    // found the user, now add his friend
    user.find({name:friend}, function(err,friendFound){
      console.log("trying to add friend to:"+guy)
      console.log("his current friends:"+guy.friends)

      guy.friends.push(friendFound.reg_id)
        callback({'response':guy.name+' is now friends with '+friendFound.name});
    })
  }); 
}

---

找到的对象是data还是null？尝试分析mongo未定义生成的对象ID时出错：1{u id:5483d815ff8b74480f7dcf85，^SyntaxError:Unexpected token{at Object.parse native at Promise.C:\Users\Arin\Documents\reference\node chat\node\node\modules\config\requests.js:76:16 JSON无效，api给出的id不带引号，因为它是一个十六进制数。JSON parse发现它是一个不带引号的字符串，所以将其删除引发错误。请尝试在_id:后加一个引号，在第一个逗号前加一个引号，看看这是否解决了问题。

exports.addfriend = function(reg_id,friend,callback) {

  user.find({reg_id:reg_id},function(err,guy){   

    // found the user, now add his friend
    user.find({name:friend}, function(err,friendFound){
      console.log("trying to add friend to:"+guy)
      console.log("his current friends:"+guy.friends)

      guy.friends.push(friendFound.reg_id)
        callback({'response':guy.name+' is now friends with '+friendFound.name});
    })
  }); 
}

trying to add friend to:{ _id: 5483d2c76dd64ee412bfe865,
  name: 'Hello',
  nick: 'hey',
  reg_id: 'XXXXXXXXX',
  __v: 0,
  friends: [] }
his current friends:undefined

C:\..\config\requests.js:82
      guy.friends.push(friendFound.reg_id)
TypeError: Cannot call method 'push' of undefined

exports.addfriend = function(reg_id,friend,callback) {

  user.find({reg_id:reg_id},function(err,guy){   
    guy = JSON.parse(guy); //ADD THIS
    // found the user, now add his friend
    user.find({name:friend}, function(err,friendFound){
      console.log("trying to add friend to:"+guy)
      console.log("his current friends:"+guy.friends)

      guy.friends.push(friendFound.reg_id)
        callback({'response':guy.name+' is now friends with '+friendFound.name});
    })
  }); 
}