Uint8Array() constructor

new Uint8Array()
new Uint8Array(length)
new Uint8Array(typedArray)
new Uint8Array(object)

new Uint8Array(buffer)
new Uint8Array(buffer, byteOffset)
new Uint8Array(buffer, byteOffset, length)

//  
const uint8 = new Uint8Array(2);
uint8[0] = 42;
console.log(uint8[0]); // 42
console.log(uint8.length); // 2
console.log(uint8.BYTES_PER_ELEMENT); // 1

// 
const x = new Uint8Array([21, 31]);
console.log(x[1]); // 31

//  TypedArray
const y = new Uint8Array(x);
console.log(y[0]); // 21

// ArrayBuffer
const buffer = new ArrayBuffer(8);
const z = new Uint8Array(buffer, 1, 4);
console.log(z.byteOffset); // 1

// 
const iterable = (function* () {
  yield* [1, 2, 3];
})();
const uint8FromIterable = new Uint8Array(iterable);
console.log(uint8FromIterable);
// Uint8Array [1, 2, 3]