[Javascript] Avoid mutation, Array.prototype.toReversed() vs reverse()

reverse()mutates the original array, return the reference point to the original array.

The toReversed() method of Array instances is the copying counterpart of the reverse() method. It returns a new array with the elements in reversed order.

const items = [1, 2, 3];
console.log(items); // [1, 2, 3]

const reversedItems = items.toReversed();
console.log(reversedItems); // [3, 2, 1]
console.log(items); // [1, 2, 3]

console.log([1, , 3].toReversed()); // [3, undefined, 1]
console.log([1, , 3, 4].toReversed()); // [4, 3, undefined, 1]