This lesson covers using your first TypeScript Interface and what happens to the Interface when it is compiled down to JavaScript.
Define the interfaces:
// interfaces.ts export interface Person { name: String } export interface SocialNetwork{ title: String; getPeople(): Person[]; }
Use interface:
import {SocialNetwork} from './interfaces'; class SocialNetworks implements SocialNetwork{ title = "Facebook"; getPeople(){ return [{name: 'John'}] } } new SocialNetworks();
To notice that, interfaces won't output to the js file, it is just used when compile time.