title: Angular 2: Default checked on checkbox in ngFor
body: <p>I'm trying to set default value as checked on a checkbox inside my ngFor.
  This is my array of checkbox items:
  </p>
  
  <pre><code>tags = [{
    name: 'Empathetic',
    checked: false
  }, {
    name: 'Smart money',
    checked: true
  }, {
    name: 'Minimal help after writing check',
    checked: false
  }, {
    name: 'Easy term sheet',
    checked: true
  }];
  </code></pre>
  
  <p>This is my html
  </p>
  
  <pre class="lang-html prettyprint-override"><code>&lt;div class="form-group"&gt;
    &lt;div class="form-check" *ngFor="let tag of tags;"&gt;
      &lt;label class="form-check-label" for="tag{{tag.value}}"&gt;
        &lt;input
          class="form-check-input"
          type="checkbox"
          id="tag{{tag.value}}"
          name="tagOptions"
          [(ngModel)]="tag.checked"&gt;
        {{tag.name}}
      &lt;/label&gt;
    &lt;/div&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>The desired result is to get 2 checked, and 2 unchecked boxes, but all of them are unchecked. I've also tried different variations with [checked]="tag.checked", but it didn't seem to do the trick.</p>