How to check the length of an Observable array

Question

In my Angular 2 component I have an Observable array

list$: Observable;

In my Template

Answer 1

A solution for .ts-Files:

     this.list.subscribe(result => {console.log(result.length)});

Answer 2

Your approach here has another major issue: by leveraging the async pipe over and over in your template, you are actually kicking off that many subscriptions to the single Observable.

KAMRUL HASAN SHAHED has the right approach above: Use the async pipe once and then provide an alias for the result that you can leverage in child nodes.