function calculateTotal(items, discountCode) {
  let total = 0;
  for (let i = 0; i < items.length; i++) {
    total = total + items[i].price; // Price might be string "10"
  }
  if (discountCode = "SAVE10") { // Bug: single = assignment
    total = total - 10;
  }
  return total;
}