JS ES5 OOP：通过构造函数中的get / set的私有实例成员

Question

I'm trying to create a constructor in a namespace (IIFE module pattern) that has a private instance member of sort that can only be changed via set/get methods. I use an IIFE that returns get/set functions that create a closure on the data, and return the get/set to the instance property. From my testing the pattern seems to work; meaning the members are private and can be accessed through the get/set only.

A) do you think this is true?

B) Are these good patterns or are there better alternatives (in ES5)?

Structure and Fiddle:

IIFE module -> constructor-> IIFE that returns get/set

Fiddle

Thanks ahead of time

//namespace 
var computerModule = (function() {
  //function constructor 
  function Computer(CPUMemory, diskMemory, CPUModel, price, warrantyInYears) {
    this.CPUMemory = CPUMemory;
    this.diskMemory = diskMemory;
    this.CPUModel = CPUModel;
  }
  Computer.prototype.buyAccessories = buyAccessories;
  Computer.prototype.print = print;
  Computer.prototype.toString = toString;

  function buyAccessories() {

  }

  function print() {
    console.log(this.toString());
  }

  function toString() {
    return `CPUMemory: ${this.CPUMemory},diskMemory: ${this.diskMemory}, CPUModel: ${this.CPUModel}, price: ${price}, warrantyInYears: ${warrantyInYears}`;
  }

  //return constructor
  return {
    Computer
  }
})();

//namespace 
var laptopComputerModule = (function() {
  //constructor
  function Laptop(CPUMemory, diskMemory, CPUModel, price, warrantyInYears, ChargingTime, ) {

    computerModule.Computer.call(this, CPUMemory, diskMemory, CPUModel, price,
      warrantyInYears);

    //trying to create a member that cannot be directly changed - need feeback
    Object.defineProperty(this, "BatteryChargingTime", {
      value: (function() {
        //private variable
        var BatteryChargingTime;
        //constructor init
        BatteryChargingTime = ChargingTime;

        function get() {
          return BatteryChargingTime;
        }

        function set(arg) {
          BatteryChargingTime = arg;
        }

        return { //functions create closuers on variables in this function, keeping its scope intact
          get,
          set
        }
      }()),
      writable: false,
      configurable: true
    })
  }
}());

Answer 1

There's no need to put an IIFE inside the constructor. The constructor function already provides a scope.

function Laptop(CPUMemory, diskMemory, CPUModel, price, warrantyInYears, ChargingTime, ) {
  computerModule.Computer.call(this, CPUMemory, diskMemory, CPUModel, price, warrantyInYears);

  this.BatteryChargingTime = {
    get: function() {
      return ChargingTime;
    },
    set: function(arg) {
      ChargingTime = arg;
    }
  }
}

Apart from that, it's a totally standard pattern. (Of course there's no point in making a "private" member that can be arbitrarily set by its setter method).