pizza

import Ember from 'ember';
import { bool } from '@ember/object/computed';

export default Ember.Controller.extend({
  appName: 'Ember Twiddle',
  undef: bool('something.undefined'),
});

pizza

import Ember from 'ember';

export default Ember.Component.extend({
  optionalVariable: 'override me!',
});

pizza

import Ember from 'ember';

export default Ember.Controller.extend({
  appName: 'Ember Twiddle',
  
  init() {
   let array1 = Em.A([Em.Object.create({
      name: 'Author name',
    })]);