When and why to use a 'tick' in Angular 2?

Question

I have seen the following is used in an Angular 2 component class:

setTimeout(()=>{}, 0);

That means, an empty function is called after

Answer 1

setTimeout(()=>{}, 0);

Causes Angular to run change detection for the whole application, like ApplicationRef.tick

zone.js patches async APIs (addEventHandler, setTimeout, ...) and runs change detection after a callback was completed.