TypedArray.prototype.set()

// ArrayBuffer 
const buffer = new ArrayBuffer(8);
const uint8 = new Uint8Array(buffer);

//  3 
uint8.set([1, 2, 3], 3);

console.log(uint8);
// : Uint8Array [0, 0, 0, 1, 2, 3, 0, 0]

set(array)
set(array, targetOffset)

set(typedarray)
set(typedarray, targetOffset)

const buffer = new ArrayBuffer(8);
const uint8 = new Uint8Array(buffer);

uint8.set([1, 2, 3], 3);

console.log(uint8); // Uint8Array [ 0, 0, 0, 1, 2, 3, 0, 0 ]