title: how can i bind to a specific array item in angular 2?
body: <p>I want to use data that has been set in an array to bind to specific input boxes. with this piece of code, I get an error:</p>
  
  <p><code>Recommendation.question</code> contains an array of questions that has been loaded through a service. This works fine, and also if just show the value of question by using the brackets it works. Just the value of the array won't bind to the input box.</p>
  
  <p>The error I Get: </p>
  
  <pre><code>Unhandled Promise rejection: Cannot assign to a reference or variable! ; Zone: &lt;root&gt; ; Task: Promise.then ; Value: ZoneAwareError Error: Cannot assign to a reference or variable!
  
    &lt;div class="list-group-item"
      *ngFor="let question of Recommendation.question; let i = index;"&gt;
      &lt;input class="form-control" name="question" [(ngModel)]="question"/&gt;
      {{question}}
      {{i}}
    &lt;/div&gt;
  </code></pre>
  
  <p>if I comment out the input field, the <code>{{question}}</code> shows the correct value that is at the current index of the array.</p>