Array.prototype.reverse()

const array = ["one", "two", "three"];
console.log("array:", array);
// : "array:" Array ["one", "two", "three"]

const reversed = array.reverse();
console.log("reversed:", reversed);
// : "reversed:" Array ["three", "two", "one"]

// : reverse 
console.log("array:", array);
// : "array:" Array ["three", "two", "one"]

reverse()

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

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

const numbers = [3, 2, 4, 1, 5];
const reversed = numbers.reverse();
// numbers and reversed are both in reversed order [5, 1, 4, 2, 3]
reversed[0] = 5;
console.log(numbers[0]); // 5

const numbers = [3, 2, 4, 1, 5];
// [...numbers]  reverse() 
const reverted = [...numbers].reverse();
reverted[0] = 5;
console.log(numbers[0]); // 3

console.log([1, , 3].reverse()); // [3, empty, 1]
console.log([1, , 3, 4].reverse()); // [4, 3, empty, 1]

const arrayLike = {
  length: 3,
  unrelated: "foo",
  2: 4,
  3: 33, // length  3  reverse() 
};
console.log(Array.prototype.reverse.call(arrayLike));
// { 0: 4, 3: 33, length: 3, unrelated: 'foo' }
//  0  2 
//  3  3