multiple checkbox

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName: 'Ember Twiddle',
  checked:[],
  grp: [
    { d: 'a' , v: false },
    { d: 'b' , v: false },
    { d: 'c' , v: false },
    { d: 'd' , v: false }
  ],
  init(){
    
    console.table(this.grp);
    
  		setTimeout( _ => {
        
      	Ember.set(this.grp[2],'v',true);

      },2000);
    
    setTimeout( _ => {
        
          console.table(this.grp);
      },5000)
  }
});

templates.application.hbs

<br>
<br>
{{outlet}}

<form>
  {{#each grp as |obj| }}
    <label>
        {{obj.d}}
    {{input type="checkbox" checked=obj.v  name="a[]" onchange=(action (mut obj.v) value="target.checked")
    
    }}
    
  
    </label>
    <br>
  {{/each}}
</form>
<br>

twiddle.json

{
  "version": "0.10.5",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "2.8.0",
    "ember-data": "2.8.0",
    "ember-template-compiler": "2.8.0",
    "ember-testing": "2.8.0"
  },
  "addons": {}
}