What is the best way to share services across Modules in angular2

Question

i want know with the help of an exmaple that What is the best way to share services across Modules in angular2?

Answer 1

In Angular 2+, it is best to share services between modules by:

Export the service in a Core or Shared module: Build a CoreModule (for singleton services) or SharedModule (for non-singleton services) and list the service in the providers array of such a module.

Use providedIn: 'root': When the service is a singleton, use the @Injectable({ providedIn: 'root' }) decorator within the service. This provides the service application-wide without having to add it to a module's providers array.

Lazy-loaded modules: For service that is particular to a feature module, implement them directly in the feature module. But with care because they can lead to multiple instances when the module is lazy-loaded.

Example:

@Injectable({

  providedIn: 'root' // Singleton service available app-wide

})

export class MyService {}