optional chaining - before

index.ts

type Person = {
  id: number;
  name: string;
  address?: Address;
}
type Address = {
  line1: string;
  line2: string;
  line3: string;
  zipcode: string;
}
function getPersonPostcode(id: number) {
  const person: Person = getPerson(id);
  return person.address.zipcode; // 💥 - Type error - Object is possibly 'undefined'
}