Javascript 如何将一个类实例推送到另一个类的私有数组中？

我的课程如下所示：

class RoomUsageList {

constructor()
{
    // private atributes
    this._roomList = [];

}

set roomList(newIns)
{
    this._roomList.push(newIns);
}
}

function saveTap()
{
// create a new class instance when the SAVE button
// is pushed.
let newAddress = document.getElementById('address').value;
let newRoomNo = document.getElementById('roomNumber').value;
let newLightSwitch = document.getElementById('lights').checked;
let newHeatCoolSwitch = document.getElementById('heatingCooling').checked;
let newSeatsUsed = document.getElementById('seatsUsed').value;
let newSeatsTotal = document.getElementById('seatsTotal').value;


let roomUsageIns = new RoomUsage();
roomUsageIns.address = newAddress;
roomUsageIns.roomNumber = newRoomNo;
roomUsageIns.lightsOn = newLightSwitch;
roomUsageIns.heatingCoolingOn = newHeatCoolSwitch;
roomUsageIns.seatsTotal = newSeatsTotal;
roomUsageIns.seatsUsed = newSeatsUsed;

// add the above-created class instance into the RoomUsageList class

let roomUsageList = new RoomUsageList(roomUsageIns);
roomUsageList.roomList = roomUsageIns;

console.log(roomUsageList);

}

以及一个函数文件（在另一个javascript文件中），该文件将另一个类（RoomUsage）的instace传递给RoomUsageList类（如上）的setter，如下所示：

class RoomUsageList {

constructor()
{
    // private atributes
    this._roomList = [];

}

set roomList(newIns)
{
    this._roomList.push(newIns);
}
}

function saveTap()
{
// create a new class instance when the SAVE button
// is pushed.
let newAddress = document.getElementById('address').value;
let newRoomNo = document.getElementById('roomNumber').value;
let newLightSwitch = document.getElementById('lights').checked;
let newHeatCoolSwitch = document.getElementById('heatingCooling').checked;
let newSeatsUsed = document.getElementById('seatsUsed').value;
let newSeatsTotal = document.getElementById('seatsTotal').value;


let roomUsageIns = new RoomUsage();
roomUsageIns.address = newAddress;
roomUsageIns.roomNumber = newRoomNo;
roomUsageIns.lightsOn = newLightSwitch;
roomUsageIns.heatingCoolingOn = newHeatCoolSwitch;
roomUsageIns.seatsTotal = newSeatsTotal;
roomUsageIns.seatsUsed = newSeatsUsed;

// add the above-created class instance into the RoomUsageList class

let roomUsageList = new RoomUsageList(roomUsageIns);
roomUsageList.roomList = roomUsageIns;

console.log(roomUsageList);

}

输出仅包含一个实例，不推送新的RoomUsage实例。为什么会这样？ 我是编程新手，任何帮助都将是惊人的

输出：

---

问题是，每次调用

saveTap

函数时，您都在创建一个新的RoomUsageList实例。这是将

\u roomList

重置为

[]

如果在函数外部调用

roomUsageList=new-roomUsageList（）

，则setter应按预期工作，并将新的

RoomUsage

实例附加到private

\u-roomList

属性

编辑：打字错误 EDIT2:在代码段中删除了额外的控制台日志

课堂使用{
构造函数（）{
//
}  
}
教室传道者{
构造函数（）{
//私人属性
这个。_roomList=[]；
}
设置房间列表（newIns）{
const roomList=[…这个。_roomList，纽因斯]；
这个。_roomList=roomList
}
}
//创建全局状态
const roomUsageList=新的roomUsageList（）；
函数onFormSubmit（事件）{
event.preventDefault（）；
//单击“保存”按钮时创建新的类实例
//被推。
让newAddress=document.querySelector（'.address'）.value；
让newRoomNo=document.querySelector（'.roomNumber'）.value；
让newLightSwitch=document.querySelector（'.lights'）。选中；
让newHeatCoolSwitch=document.querySelector（'.heatingCooling'）。选中；
让newSeatsUsed=document.querySelector（'.seatsUsed'）.value；
让newSeatsTotal=document.querySelector（'.seatsTotal'）.value；
let roomUsageIns=新的RoomUsage（）；
roomUsageIns.address=新地址；
roomUsageIns.roomNumber=newRoomNo；
roomUsageIns.lightsOn=newLightSwitch；
roomUsageIns.heatingCoolingOn=新建加热冷却开关；
roomUsageIns.seatsTotal=newSeatsTotal；
roomUsageIns.seatsUsed=使用的新闻；
//将上面创建的类实例添加到RoomUsageList类中
roomUsageList.roomList=roomUsageIns；
控制台日志（roomUsageList）；
}

地址
房间号
灯
加热/冷却
使用的座位
座位总数
拯救

感谢您的帮助，通过稍微调整代码，程序运行得非常完美。这就是我所做的：

//Room Usage List Class
//---------------------
//
class RoomUsageList {

constructor()
{
    // private atributes
    this._roomList = [];

}

set roomList(newIns)
{
    // pushes new array into parent class instance
    this._roomList.push(newIns);
}  
}

//making the parent class instance global
const roomUsageList = new RoomUsageList();

function saveTap()
{
// create a new class instance when the SAVE button
// is pushed.
let newAddress = document.getElementById('address').value;
let newRoomNo = document.getElementById('roomNumber').value;
let newLightSwitch = document.getElementById('lights').checked;
let newHeatCoolSwitch = document.getElementById('heatingCooling').checked;
let newSeatsUsed = document.getElementById('seatsUsed').value;
let newSeatsTotal = document.getElementById('seatsTotal').value;

let roomUsageIns = new RoomUsage();
roomUsageIns.address = newAddress;
roomUsageIns.roomNumber = newRoomNo;
roomUsageIns.lightsOn = newLightSwitch;
roomUsageIns.heatingCoolingOn = newHeatCoolSwitch;
roomUsageIns.seatsTotal = newSeatsTotal;
roomUsageIns.seatsUsed = newSeatsUsed;

// add the above created class instance into the RoomUsageList class
roomUsageList.roomList = roomUsageIns;
console.log(roomUsageList);

}

---

您应该仅使用

setter

来设置整个列表，而不是附加项-为此，您可以创建单独的方法，例如用于附加单个项的

addItem

，或将多个项插入数组的

addItems

class RoomUsageList {

  constructor() {
    this._roomList = [];
  }

  set roomList(roomList) {
    this._roomList = roomList;
  }

  addItem(item) {
    this._roomList.push(item);
  }

  addItems(items) {
    this._roomList.concat(items);
  }
}

---

很好，您找到了解决方案—每次调用函数都会创建新实例：）

它正在推送新实例。您只是没有在构造函数中使用参数。代码正在按预期工作。我想你的问题是每次调用

saveTap

时都要重新定义

roomUsageList

。实际上你的

RoomUsage

类应该有一个

.roomList

属性。根本不应该有

RoomUsageList

课程。保持简单。如果要

将
（附加）推送到列表中，请不要使用setter。或者，如果您不想附加到setter中的列表，但要覆盖列表，请完全删除setter。感谢您注意到这一点。但是在尝试代码之后，通过创建新数组、在数组中、在数组中等等来推送新数组。我刚刚修改了你的代码，现在它工作得很好，再次感谢你的帮助！（我添加了我刚才所做的作为对这个问题的回答）。嗯，当我运行我的代码片段时，情况并非如此。我的代码使用spread操作符来确保一个平面列表：
constroomlist=[…this.\u roomList，newIns]你也这么做了吗？无论如何，我认为DarekGala的答案是更好的API设计。应使用setter设置值，而不是部分修改它。因此，最好使用公共方法从私有列表中添加/删除元素。