title: Not showing li in ngFor statement
body: <p>I am trying to write a pager.</p>
  
  <p>I would like to not put the <code>&lt;li&gt;</code> element to the dom if <code>number=-1</code>. </p>
  
  <p>I could not write <code>ngIf</code> inside an <code>ngFor</code> so if anyone could show me the way I would appreciate it.</p>
  
  <p>Here is what I'd like to improve:</p>
  
  <pre class="lang-html prettyprint-override"><code>&lt;li *ngFor="let number of pagerArray" class="page-item"&gt;
    &lt;a class="page-link" href="#"&gt;{{number}}&lt;/a&gt;
  &lt;/li&gt;
  </code></pre>