Interfaces y Clases

Interfaces

interface Person {
  firstName: string;
  lastName: string;
}

function greeter(person: Person) {
  return "Hello, " + person.firstName + " " + person.lastName;
}

let user = { firstName: "John", lastName: "Doe" };
console.log(greeter(user));

Clases

class Greeter {
  greeting: string;
  constructor(message: string) {
    this.greeting = message;
  }
  greet() {
    return "Hello, " + this.greeting;
  }
}

let greeter = new Greeter("world");
console.log(greeter.greet());