Ember CPs

application.controller.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName:'Ember Twiddle',
  p1: Ember.computed({
  	get() { return 42; }
  }),
  p2: Ember.computed({
  	get() { return 42; },
  	set() { return 24; }
  }),
  p3: Ember.computed({
  	get() { return 42; },
  	set() { return 24; }
  }),
  _init: function () {
  	this.set('p1', '44');
  	this.set('p2', '43');
  	this.set('p3', '43');
  	this.set('p4', this.get('p3'));
  }.on('init')
});

application.template.hbs

<h1>Welcome to {{appName}}</h1>
<br>
<br>
{{p1}}
{{p2}}
{{p3}}
{{p4}}
<br>
<br>

twiddle.json

{
  "version": "0.4.10",
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "https://cdnjs.cloudflare.com/ajax/libs/ember.js/1.13.9/ember.debug.js",
    "ember-data": "https://cdnjs.cloudflare.com/ajax/libs/ember-data.js/1.13.11/ember-data.js",
    "ember-template-compiler": "https://cdnjs.cloudflare.com/ajax/libs/ember.js/1.13.9/ember-template-compiler.js"
  }
}