无法调用未定义的方法推送（定义时）

Question

我使用Node.js和mongoose为应用程序创建后端，用户可以在其中互相通信。

架构

var mongoose = require('mongoose'); 

    var Schema = mongoose.Schema; 

    var userSchema = mongoose.Schema({ 
    name : String, 
    nick: String, 
    reg_id: String, 
    friends: { 
     type: Array, 
     'default': [] 
    } 
    }); 
    mongoose.connect('mongodb://localhost:27017/DB'); 
    module.exports = mongoose.model('users', userSchema); 

请求

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}); 
    }) 
    }); 
} 

控制台为什么限定

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 

表示了阵列当它在模式中定义并且我正在回顾正确的用户（家伙）时？感谢您的帮助

Answer 1

看来，你的家伙对象实际上是一串JSON而不是JSON对象。尝试在其上运行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}); 
    }) 
    }); 
}