title: Iterate 2 mixed arrays in async
body: <p>Please check the code:</p>
  
  <pre><code>export class SomePage {
    uids:Observable&lt;any[]&gt;;
    uamt:Observable&lt;any[]&gt;;
  
    constructor(private db: AngularFireDatabase) {
            this.uids = this.db.list('data/request').snapshotChanges().map(changes =&gt; {
                  return changes.map(c =&gt; ({ key: c.payload.key, ...c.payload.val() }));
                  });
            }
  
            this.uamt = this.db.list('data/account').snapshotChanges().map(changes =&gt; {
                      return changes.map(c =&gt; ({ key: c.payload.key, ...c.payload.val() }));
                  });
            }
  </code></pre>
  
  <p><strong>Possible without piping?</strong></p>
  
  <pre><code>//some.html
  &lt;ion-row *ngFor="let ud of uids | async; let bl of uamt | async"&gt;
  </code></pre>
  
  <p><strong>If i need to add piping how to do that?</strong></p>