const values = [0, 1, '', 'hello', null, undefined, false];
const filtered = values.filter(Boolean);
console.log(filtered.length);

.image {
  filter: grayscale(100%) brightness(1.2) contrast(1.5);
}

const obj = { a: 1, b: 2, c: 3 };
const mapped = Object.fromEntries(
  Object.entries(obj).map(([k, v]) => [k, v * 2])
);
console.log(mapped.b);

const div = document.querySelector('.container');
const width = div.offsetWidth;
const height = div.clientHeight;
console.log(typeof width, typeof height);

.card {
  transform: rotate(45deg) scale(1.5);
}

const arr = [1, [2, 3], [4, [5, 6]]];
const flat = arr.flat(Infinity);
console.log(flat.length);

const p1 = Promise.resolve(10);
const p2 = Promise.reject('Error');
const p3 = Promise.resolve(20);
Promise.allSettled([p1, p2, p3]).then(results => console.log(results.length));

.image {
  clip-path: circle(50%);
}

const arr = [1, 2, 3];
const result = arr.flatMap(x => [x, x * 2]);
console.log(result);

const symbol1 = Symbol('id');
const symbol2 = Symbol('id');
const obj = { [symbol1]: 'value1' };
console.log(symbol1 === symbol2, obj[symbol1]);