typescript

Classes

In a hero.ts file, then import it everywhere you use it

export class Hero {
  id: number;
  name: string;
}

Services:

providers: [HeroService] in app.module.ts

constructor(private heroService: HeroService) {
}

ngOnInit() {
  this.heroes = this.heroService.getHeroes();
}

• In a class, public if you use it in the html or something

• Define getHeroes in the service