Misspelling length in a for loop in a function doesn’t throw an exception. Why? [duplicate]

function multiplyAll(arr) {
  let product = 1;

  for (let i = 0; i < arr.lenght; i++) {
    for (let j = 0; j < arr[i].length; j++) {
      product = product * arr[i][j];
      //console.log(product);
    }
  }

  return product;
}

In the first for loop length has been misspelt but the the code doesn’t throw any error and does not even run.