async function asyncFunc() {
  return 'async';
}

function promiseFunc() {
  return new Promise(resolve => resolve('promise'));
}

(async function() {
  const result = await (true ? asyncFunc() : promiseFunc());
  console.log(result);
})();

const obj1 = {
  a: 1,
  method() {
    return this.a;
  }
};

const obj2 = Object.create(obj1);
obj2.a = 2;

console.log(obj2.method());

async function asyncFunc() {
  return 'async function';
}

function* generator() {
  yield 'generator';
  yield asyncFunc();
  yield 'done';
}

const gen = generator();
(async function() {
  console.log(gen.next().value);
  console.log(await gen.next().value);
  console.log(gen.next().value);
})();

const obj1 = { a: 1 };
const obj2 = Object.create(obj1);
obj2.b = 2;

console.log(obj2.a, obj2.b);
console.log(obj2.hasOwnProperty('a'));
console.log(Object.getPrototypeOf(obj2) === obj1);

const array = [1, 2, 3, 4, 5];
const result = array.filter(n => n % 2).map(n => n * 2);

console.log(result);

const arr = [1, 2, 3, 4, 5];
const [first, , third, ...rest] = arr;

console.log(first, third, rest);

const obj = {};
let value = 0;

Object.defineProperty(obj, 'prop', {
  get() {
    return value;
  },
  set(newValue) {
    value = newValue + 1;
  },
  configurable: true,
  enumerable: true
});

obj.prop = 10;
console.log(obj.prop);