title: Angular 2 set and bind checkboxes with a ngFor
body: <p>I have an array like this:   </p>
  
  <pre><code> objectArray = [
          {"name": "Car"},
          {"name": "Bike"},
          {"name": "Boat"},
          {"name": "Plane"}
      ];
  </code></pre>
  
  <p>And the template like this: </p>
  
  <pre><code>&lt;li *ngFor="#obj of objectArray"&gt;
     &lt;a href="#" class="small" data-value="option1" tabIndex="-1"&gt;
        &lt;input type="checkbox" (change)="expression &amp;&amp; expression.value = $event.target.checked ? true : undefind" [ngModel]="expression?.value"&gt;
        &lt;label for=""&gt;{{ obj.name }}&lt;/label&gt;
     &lt;/a&gt;
  &lt;/li&gt;
  </code></pre>
  
  <p>But this is set true when 1 checkbox is checked. How do i set this separately ?</p>