title: how to loop with out a collection in angular 2
body: <p>I have a number and I want to iterate that number of times.</p>
  
  <pre><code>for (var _i = 0; _i &lt; length; _i++)
  </code></pre>
  
  <p>I want to implement similar to this syntax in the html template. if i use ngFor then i will need to have a collection but I don't have collection, I just have length.</p>