TypedArray.prototype.findLast()

function isNegative(element /*, index, array */) {
  return element < 0;
}

const int8 = new Int8Array([10, 0, -10, 20, -30, 40, 50]);

console.log(int8.find(isNegative));
// Expected output: -30

findLast(callbackFn)
findLast(callbackFn, thisArg)

function isPrime(element) {
  if (element % 2 === 0 || element < 2) {
    return false;
  }
  for (let factor = 3; factor <= Math.sqrt(element); factor += 2) {
    if (element % factor === 0) {
      return false;
    }
  }
  return true;
}

let uint8 = new Uint8Array([4, 6, 8, 12]);
console.log(uint8.findLast(isPrime)); // undefined (   )
uint8 = new Uint8Array([4, 5, 7, 8, 9, 11, 12]);
console.log(uint8.findLast(isPrime)); // 11

//  2,3,4    
//   0  .
const uint8 = new Uint8Array([0, 1, , , , 5, 6]);

//   .
//      .
uint8.findLast((value, index) => {
  console.log(`Visited index ${index} with value ${value}`);
});

//      
uint8.findLast((value, index) => {
  //    3 
  if (index === 6) {
    console.log("Set uint8[3] to 44");
    uint8[3] = 44;
  }
  //  3     
  console.log(`Visited index ${index} with value ${value}`);
});
// Visited index 6 with value 6
// Visited index 5 with value 5
// Visited index 4 with value 0
// Visited index 3 with value 0
// Visited index 2 with value 0
// Visited index 1 with value 1
// Visited index 0 with value 0
// Set uint8[3] to 44
// Visited index 6 with value 6
// Visited index 5 with value 5
// Visited index 4 with value 0
// Visited index 3 with value 44
// Visited index 2 with value 0
// Visited index 1 with value 1
// Visited index 0 with value 0