title: Set value of ngmodel using index in ng-repeat
body: <p>I have this array and iterate the value using ng-repeat. Using ng-repeat I would be able to use $index which represent the iterator. </p>
  
  <p>Before I have this code where the user input the question order number:</p>
  
  <pre><code>&lt;div ng-repeat="q in entries"&gt;
    &lt;input type="text" ng-model="q.orderNo"&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>But the client requested for a draggable feature, to drag drop the questions to be sorted out. eg. the user dragged Question #1 to Question #2 place then their place will change thus the question order number will re-index. With this the user input for order number won't be needed no more but I still have to set the q.orderNo and bind the $index to it when I passed to my api. </p>
  
  <pre><code>&lt;div ng-repeat="q in entries"&gt;
    &lt;input type="text" ng-model="q.orderNo = $index"&gt; //this is what I want to accomplish
  &lt;/div&gt;
  </code></pre>
  
  <p>I want to assign the $index to q.orderNo, how would I do that?</p>