give array to child component

application.controller.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName:'Ember Twiddle'
});

application.template.hbs

<h1>Welcome to {{appName}}</h1>
<br>
<br>
{{parent-component}}
<br>
<br>

child-component.component.js

import Ember from 'ember';

export default Ember.Component.extend({
  actions: {
    checkArr() {
      alert(this.get('childArr') instanceof Array);
    }
  }
});

child-component.template.hbs

<button {{action 'checkArr'}}>checkArr</button>

parent-component.component.js

import Ember from 'ember';

export default Ember.Component.extend({
  parentArr: Ember.computed({
    get() {
      return ['a','b','c'];
    }
  })
});

parent-component.template.hbs

{{child-component childArr=parentArr}}

twiddle.json

{
  "version": "0.5.3",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "https://cdnjs.cloudflare.com/ajax/libs/ember.js/2.3.1/ember.debug.js",
    "ember-data": "https://cdnjs.cloudflare.com/ajax/libs/ember-data.js/2.3.3/ember-data.js",
    "ember-template-compiler": "https://cdnjs.cloudflare.com/ajax/libs/ember.js/2.2.0/ember-template-compiler.js"
  }
}