title: How to create ng-model array with ng-repeat(number)
body: <p>I have 2 step form </p>
  
  <p>on step 1 : ask user to how many input form needed </p>
  
  <p>that use in <code>&lt; input type="number" ng-model="vm.nkeys"</code> />`</p>
  
  <p>on step 2 : want to create one input text for each with <em>ng-model</em> and <em>name</em> attribute in array form so that I can capture the every input box value; but both is not working; see the relevant code and wokrking plunker below.</p>
  
  <pre><code>&lt;div ng-show="vm.step == 2" ng-form="vm.step2form" class="step-content body" &gt;
        &lt;div class="text-center m-t-md"&gt;
           &lt;div ng-repeat="n in [].constructor(vm.nkeys) track by $index" class="form-group"&gt;
              &lt;label class="col-sm-2 control-label"&gt;{{$index+1}}&lt;/label&gt;
                &lt;input ng-model="key_desc" name="description_{{n}}" type="text" class="form-control" &gt;
            &lt;/div&gt;
        &lt;/div&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>tried  <code>ng-model="key_desc[{{$index+1}}]</code> but no success; also <code>name=description_{{$index}}</code> is also not working</p>
  
  <p>see the <a href="https://plnkr.co/edit/zyWAy5NsshxzDP6Vhygt?p=preview" rel="nofollow">demo plunker</a> </p>
  
  <p>what do I need to do?</p>