// A
function myFunc() {}

// B
const myFunc = () => {}

// C
const myFunc = function internalName() {}

// D
(function() {})()

function foo(a, b = 1, c) {}

console.log(foo.length);

const factorial = function calc(n) {
    if (n <= 1) return 1;
    return n * calc(n - 1);
};

console.log(factorial(5));
console.log(typeof calc);

const arr = [1, 2, , 4, [5, , 7]];
console.log(arr.flat());

const [a, ...[b, _, ...c]] = [1, 2, 3, 4, 5];
console.log(a, b, c);