JS: Array.prototype.at

(new in ECMAScript 2022)

xArray.at(n)

• return the element at index n
• n can be negative, meaning counting from right.

🟢 TIP: similar to xArray[n], but allow negative index.

console.assert([1, 2, 3, 4, 5].at(-1) === 5);

// example of Array.prototype.at on array-like object
console.assert(
 (Reflect.apply(
  Array.prototype.at,
  { 0: "a", 1: "b", length: 2 },
  [0],
 )) === "a",
);