title: Get index of outer *ngFor in nested *ngFor
body: <p>I am trying to get the index of the outer *ngFor in the nested *ngFor. Attaching the code below:</p>
  
  <pre><code>&lt;div *ngFor="let st of s;let i = index"&gt;
          &lt;span *ngFor="let indexnumber of i"&gt;&amp;nbsp;&lt;/span&gt;   //i is the index of above *ngFor
          &lt;/span&gt;
        {{st}}
  &lt;/div&gt;
  </code></pre>
  
  <p>What I get on doing this is an error: <strong>Cannot find a differ supporting object '1' of type 'number'. NgFor only supports binding to Iterables such as Arrays.</strong></p>
  
  <p>How can I achieve this scenario?</p>