Array example

controllers.application.js

import Ember from 'ember';
import EmberObject from '@ember/object';

const myArr = [1,2,3,4,5].map(i => EmberObject.create({name: 'Name'+i, age: (i+1)*10}));
const someData = {
  myArr
};

export default Ember.Controller.extend({
  someData,
  appName: 'Ember Twiddle',
  actions: {
  	plusTen(el){
      console.log(el);
      el.set('age', el.age+10);
    	//set(el, 'age', age+10);
    }
  }
});

templates.application.hbs

<h1>Welcome to {{appName}}</h1>
<br>
<br>
<table>
{{#each someData.myArr as |el|}}
<tr>{{el.name}}<td></td> <td>{{el.age}}</td> <td><button {{action 'plusTen' el}}>Plus 10</button></td> </tr>
{{/each}}
</table>
{{outlet}}
<br>
<br>

twiddle.json

{
  "version": "0.14.1",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.js",
    "ember": "2.18.2",
    "ember-template-compiler": "2.18.2",
    "ember-testing": "2.18.2"
  },
  "addons": {
    "ember-data": "2.18.2"
  }
}