[JavaScript] Optional Chaining (?.)

const weekdays = ['mon', 'tue', 'wed', 'thu', 'fri', 'sat', 'sun'];
const openingHours = {
  [weekdays[3]]: {
    open: 12,
    close: 22,
  },
  [weekdays[4]]: {
    open: 11,
    close: 23,
  },
  [weekdays[5]]: {
    open: 0, // Open 24 hours
    close: 24,
  },
};

const restaurant = {
  name: 'Classico Italiano',
  location: 'Via Angelo Tavanti 23, Firenze, Italy',
  categories: ['Italian', 'Pizzeria', 'Vegetarian', 'Organic'],
  starterMenu: ['Focaccia', 'Bruschetta', 'Garlic Bread', 'Caprese Salad'],
  mainMenu: ['Pizza', 'Pasta', 'Risotto'],

  // ES6 enhanced object literals
  openingHours,

  order(starterIndex, mainIndex) {
    return [this.starterMenu[starterIndex], this.mainMenu[mainIndex]];
  },

  orderDelivery({ starterIndex = 1, mainIndex = 0, time = '20:00', address }) {
    console.log(
      `Order received! ${this.starterMenu[starterIndex]} and ${this.mainMenu[mainIndex]} will be delivered to ${address} at ${time}.`
    );
  },

  orderPasta(ing1, ing2, ing3) {
    console.log(`Here is your delicious pasta with ${ing1}, ${ing2}, ${ing3}.`);
  },

  orderPizza(mainIngredient, ...otherIngredients) {
    console.log(mainIngredient);
    console.log(otherIngredients);
  },
};

if (restaurant.openingHours && restaurant.openingHours.mon)
  console.log(restaurant.openingHours.mon.open);

// WITH optional chaining
console.log(restaurant.openingHours.mon?.open);
console.log(restaurant.openingHours?.mon?.open);
console.log(restaurant.openingHours.fri?.open);
console.log(restaurant.openingHours?.thu?.open);

//example
const days = ['mon', 'tue', 'wed', 'thu', 'fri', 'sat', 'sun'];

for (const day of days) {
  const open = restaurant.openingHours[day]?.open ?? 'closed';
  console.log(`On ${day}, we open at ${open}`);
}

// Methods
console.log(restaurant.order?.(0, 1) ?? 'Method does not exist');
console.log(restaurant.orderRisotto?.(0, 1) ?? 'Method does not exist');

// Arrays
const user = [{ name: 'Jonas', email: 'hello@jonas.io' }];

// const user = [];

console.log(user[0]?.name ?? 'User array empty');

if (user.length > 0) console.log(user[0].name);
else console.log('User array empty');