JavaScript从子类设置父值

Question

I am in JavaScript.

Below I have a Main object that instantiates the Handle class within it. I prefer composition over inheritance which is why I've avoided prototyping -- unless there is a way around it..

function Main() {

  this.changeMe = 1;

  this.init = function() {
    handle = new Handle();
    handle.setMe();

  }
};

function Handle() {
  this.setMe = function() {
     // parent::changeMe = 2; <-- How would I change the parent value?    
  }
};

var app = new Main();
main.init();
console.log(main.changeMe); <-- How do I get that to 2?

I am trying to figure out how I change the parent value. Do you know how?

Answer 1

The init code is wrong here, syntax error.. You are creating new object of Main() in app variable yet trying to access it from 'main' variable which is not initialized.

try

var app = new Main();
app.init();
console.log(app.changeMe);