Error when trying to inject a service into an angular component “EXCEPTION: Can't resolve all parameters for component”, why?

Question

I\'ve built a basic app in Angular, but I have encountered a strange issue where I cannot inject a service into one of my components. It injects fine into any of the three o

Answer 1

for angular 6 and newer versions, try

@Injectable({
  providedIn: 'root'
})

..right above your service class with no other lines in between

advantages

• no need to add the service to any module (will be "auto-discovered")
• service will be a singleton (since it will be injected into root)

[angular docs]