Same Array

components.same-array.js

import Ember from 'ember';

export default Ember.Component.extend({
  counter: 0,	
  internalArray: [],
  actions: {
    addItem() {
      const newCount = this.get('counter') + 1;
    	this.get('internalArray').pushObject(newCount);
      this.set('counter', newCount);
    },
  },
});

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
});

templates.application.hbs

{{same-array}}
<hr/>
{{same-array}}

templates.components.same-array.hbs

<div>
<button {{action 'addItem'}}>Add Item</button>
</div>
<ol>
  {{#each internalArray as |item|}}
    <li>{{item}}</li>
  {{/each}}
</ol>
  

twiddle.json

{
  "version": "0.12.1",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "2.12.0",
    "ember-template-compiler": "2.12.0",
    "ember-testing": "2.12.0"
  },
  "addons": {
    "ember-data": "2.12.1"
  }
}