hash helper

components.my-component.js

import Ember from 'ember';

export default Ember.Component.extend({
  prettyParams: Ember.computed('params', {
    get() {
      return `${this.get('params.paramA')} && ${this.get('params.paramB')}`;
    }
  })
});

controllers.application.js

import Ember from 'ember';

function random() {
  return Math.round(Math.random() * 100);
}

export default Ember.Controller.extend({
  appName: 'Ember Twiddle',
  paramA: random(),
  paramB: random(),
  
  actions: {
    randomize() {
      this.set('paramA', random());
      this.set('paramB', random());
    }
  }
});

templates.application.hbs

<h1>Welcome to {{appName}}</h1>
<br>
paramA: {{paramA}}
<br>
paramB: {{paramB}}
<br>
<button onclick={{action "randomize"}}>Randomize</button>
<br>
{{my-component params=(hash paramA=paramA paramB=paramB)}}

templates.components.my-component.hbs

{{yield}}
prettyParams: {{prettyParams}}
<br>
<br>

twiddle.json

{
  "version": "0.8.1",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "2.5.1",
    "ember-data": "2.5.2",
    "ember-template-compiler": "2.5.1"
  }
}