daubattu

// Written as of ES2019
await Promise.resolve(console.log('🎉')); // → SyntaxError: await is only valid in async function

(async function() {
  await Promise.resolve(console.log('🎉')); // → 🎉
}());

// Top level await
await Promise.resolve(console.log('🎉')); // → 🎉

daubattu

const number1 = 10;
const number2 = 0;

// Written as of ES2019
const score1 = number1 || 1;
console.log(score1); // 10
const score2 = number2 || 1;
console.log(score2); // 1

// Using nullish coalescing

daubattu

class User {
  #salary = 1000;
}

const newUser = new User();
console.log(newUser.salary) // undefined

daubattu

// Written as of ES2019
if (onError) { // Testing if onError really exists
  onError();
}

// Using optional chaining with function calls
onError?.(); // no exception if onError is undefined

daubattu

const users = [
  {
    name: 'Nguyễn Hưng Khánh',
    girl_friend: {
      name: 'Nguyễn Thị Khánh',
      address: 'Hà Nội'
    }
  },
  {
    name: 'Nguyễn Văn Khánh'

daubattu

console.log(users[1]?.girl_friend?.name)
// output: undefined

daubattu

// users[0]
console.log(users[0].girl_friend.name)

// users[1]
if (users[1].girl_friend) {
  console.log(users[1].girl_friend.name)
} else {
  console.log('Lêu lêu. Thằng này ê sắc ế')
}

daubattu

const users = [
  {
    id: 1,
    name: 'Nguyễn Hưng Khánh',
    girl_friend: {
      name: 'Nguyễn Thị Khánh',
      address: 'Hà Nội'
    }
  },
  {

daubattu

function getMoneySpent(keyboards, drives, b) {
    /*
     * Write your code here.
     */
    let max = -1;
     
    for(let i = 0; i < keyboards.length; i++) {
        const keyboardPrice = keyboards[i];
        for(let j = 0; j < drives.length; j++) {
            const drivePrice = drives[j];

daubattu

function pageCount(n, p) {
    /*
     * Write your code here.
     */
    const pageFromStart = Math.floor(p/2);
    const pageFromEnd = Math.ceil(((n % 2 !== 0 ? n - 1 : n) - p)/2);
    return Math.min(pageFromStart, pageFromEnd);
}