Array.prototype.at()

const array1 = [5, 12, 8, 130, 44];

let index = 2;

console.log(`An index of ${index} returns ${array1.at(index)}`);
// Expected output: "An index of 2 returns 8"

index = -2;

console.log(`An index of ${index} returns ${array1.at(index)}`);
// Expected output: "An index of -2 returns 130"

at(index)

//   
const cart = ["apple", "banana", "pear"];

// ,      
function returnLast(arr) {
  return arr.at(-1);
}

//      'cart'
const item1 = returnLast(cart);
console.log(item1); // : 'pear'

//      'cart'
cart.push("orange");
const item2 = returnLast(cart);
console.log(item2); // : 'orange'

//    
const colors = ["red", "green", "blue"];

//   'length'
const lengthWay = colors[colors.length - 2];
console.log(lengthWay); // : 'green'

//   slice().  ,   
const sliceWay = colors.slice(-2, -1);
console.log(sliceWay[0]); // : 'green'

//   at()
const atWay = colors.at(-2);
console.log(atWay); // : 'green'

const arrayLike = {
  length: 2,
  0: "a",
  1: "b",
};
console.log(Array.prototype.at.call(arrayLike, -1)); // "b"