How to "subscribe" to variables instead of just use them?

[AaronSterling]

Injecting services best practises

private _example: BehaviorSubject<number> = new BehaviorSubject<number>(5); // update example this._example.next(6); // method exposed in provider for pages to use exampleStream(): Observable<number> { return this._example.asObservable(); } // in a page exampleLocalCopy: number; this.exampleProvider.exampleStream().subscribe(ex => this.exampleLocalCopy = ex);