我有一个类,如下所示:
class RoomUsageList {
constructor()
{
// private atributes
this._roomList = [];
}
set roomList(newIns)
{
this._roomList.push(newIns);
}
}
还有一个函数文件(在另一个 javascript 文件中),它将另一个类 (RoomUsage) 的实例传递给 RoomUsageList 类(上面)的 setter,如下所示:
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,并且不会推送新的 RoomUsage 实例。为什么会这样? 我是编程新手,任何帮助都会很棒!
输出:
最佳答案
问题是,每次调用 saveTap
函数时,您都会创建一个新的 RoomUsageList 实例。这会将 _roomList
重置为 []
。
如果您在函数外部调用 roomUsageList = new RoomUsageList()
,则 setter 应按预期工作,并将新的 RoomUsage
实例附加到私有(private) _roomList
属性。
编辑:错别字 EDIT2:删除了代码片段中的额外控制台日志
class RoomUsage {
constructor () {
//
}
}
class RoomUsageList {
constructor () {
// private attributes
this._roomList = [];
}
set roomList(newIns) {
const roomList = [...this._roomList, newIns];
this._roomList = roomList
}
}
// Create global state
const roomUsageList = new RoomUsageList();
function onFormSubmit (event) {
event.preventDefault();
// create a new class instance when the SAVE button
// is pushed.
let newAddress = document.querySelector('.address').value;
let newRoomNo = document.querySelector('.roomNumber').value;
let newLightSwitch = document.querySelector('.lights').checked;
let newHeatCoolSwitch = document.querySelector('.heatingCooling').checked;
let newSeatsUsed = document.querySelector('.seatsUsed').value;
let newSeatsTotal = document.querySelector('.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);
}
<form onsubmit="onFormSubmit(event)">
<div>
<label>Address</label>
<input type="text" class="address">
</div>
<div>
<label>Room Number</label>
<input type="text" class="roomNumber">
</div>
<div>
<label>Lights</label>
<input type="text" class="lights">
</div>
<div>
<label>
<input type="checkbox" class="heatingCooling">
Heating/Cooling
</label>
</div>
<div>
<label>Seats Used</label>
<input type="text" class="seatsUsed">
</div>
<div>
<label>Seats Total</label>
<input type="text" class="seatsTotal">
</div>
<button type="submit">Save</button>
</form>
关于javascript - 如何将一个类实例插入另一个类的私有(private)数组中?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/52452762/