const obj = {
  name: "Nikola",
  greetArrow: () => {
    return `Hello, ${this?.name ?? "stranger"}!`;
  },
  greetRegular() {
    return `Hello, ${this.name}!`;
  },
  greetNested() {
    const inner = () => `Hi, ${this.name}!`;
    return inner();
  }
};

console.log(obj.greetArrow());
console.log(obj.greetRegular());
console.log(obj.greetNested());