TypedArray.prototype.map()

const uint8 = new Uint8Array([25, 36, 49]);
const roots = uint8.map(Math.sqrt);
console.log(roots);
// Expected output: Uint8Array [5, 6, 7]

map(callbackFn)
map(callbackFn, thisArg)

const numbers = new Uint8Array([1, 4, 9]);
const roots = numbers.map(Math.sqrt);
// roots の内容は [1, 2, 3] となる
// numbers の内容は [1, 4, 9] のまま

const numbers = new Uint8Array([1, 4, 9]);
const doubles = numbers.map((num) => num * 2);
// doubles は Uint8Array [2, 8, 18] となる
// numbers は Uint8Array [1, 4, 9] のまま