const firstPromise = new Promise((res, rej) => {
  setTimeout(res, 500, 'one');
});

const secondPromise = new Promise((res, rej) => {
  setTimeout(res, 100, 'two');
});

Promise.race([firstPromise, secondPromise]).then(res => console.log(res));

let person = { name: 'Lydia' };
const members = [person];
person = null;

console.log(members);

const person = {
  name: 'Lydia',
  age: 21,
};

for (const item in person) {
  console.log(item);
}

[1, 2, 3].map(num => {
  if (typeof num === 'number') return;
  return num * 2;
});

function getInfo(member, year) {
  member.name = 'Lydia';
  year = '1998';
}

const person = { name: 'Sarah' };
const birthYear = '1997';

getInfo(person, birthYear);

console.log(person, birthYear);

function greeting() {
  throw 'Hello world!';
}

function sayHi() {
  try {
    const data = greeting();
    console.log('It worked!', data);
  } catch (e) {
    console.log('Oh no an error:', e);
  }
}

sayHi();

function Car() {
  this.make = 'Lamborghini';
  return { make: 'Maserati' };
}

const myCar = new Car();
console.log(myCar.make);

(() => {
  let x = (y = 10);
})();

console.log(typeof x);
console.log(typeof y);

class Dog {
  constructor(name) {
    this.name = name;
  }
}

Dog.prototype.bark = function() {
  console.log(`Woof I am ${this.name}`);
};

const pet = new Dog('Mara');

pet.bark();

delete Dog.prototype.bark;

pet.bark();