New Twiddle

controllers.application.js

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

export default Ember.Controller.extend({
  appName: 'Ember Twiddle',
  
  test: computed('{bla,la}', function() {
  	return `${this.bla},${this.la}`;
	}),
  
  actions: {
  	incrementBla() {
  		this.incrementProperty('bla');
		},
    
    incrementLa() {
  		this.incrementProperty('la');
		}
	}
});

templates.application.hbs

Test<br />
{{test}}

<br />
<button {{action 'incrementBla'}}> +1 first elemenet</button>
<button {{action 'incrementLa'}}> +1 second elemenet</button>

twiddle.json

{
  "version": "0.15.1",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.js",
    "ember": "3.4.3",
    "ember-template-compiler": "3.4.3",
    "ember-testing": "3.4.3"
  },
  "addons": {
    "ember-data": "3.4.2"
  }
}