我重復出現這樣的錯誤：error: use of undeclared identifier 'item'和"error: expected unqualified-idcin.getline(*(cart->(item+i)->itemName), SIZE1);。當我在一個結構中訪問一個結構時，我將指針表示法與箭頭運算符一起使用。我知道我只填充了ShoppingCart類型的cart變量的一些成員，但是我不認為問題是從這里來的。我訪問ItemInfo類型的item變量的成員的方式似乎是錯誤的。不過，我不知道我的錯誤在哪里。如果有人能幫助我，我將不勝感激。我的代碼在這里：

#include <iostream>
using namespace std;

const int SIZE1 = 51,
          SIZE2 = 11,
          SIZE3 = 21;
struct ItemInfo
{
  char itemName[SIZE1];
  char itemID[SIZE2];
  double price;
};
struct ShoppingCart
{
  char shopperName[SIZE3];
  ItemInfo *item;
  int *itemCount;
  double total;
};
void addToCart(ShoppingCart* cart);

int main()
{
  ShoppingCart* cart = new ShoppingCart;

  cart->item = nullptr;

  addToCart(cart);

  delete [] cart->item;
  delete [] cart->itemCount;
  delete cart;
  return 0;
}

void addToCart(ShoppingCart* cart)
{
  int numItems;

  cout << "How many items are you purchasing?";
  cin >> numItems;

  cart->item = new ItemInfo[numItems];
  cart->itemCount = new int[numItems];

  for(int i = 0; i < numItems; i++)
  {
    cout << "\nEnter #" << i+1 << " item name: ";
    cin.getline(*(cart->(item+i)->itemName), SIZE1);

    cout << "\nEnter #" << i+1 << " item ID: ";
    cin.getline(*(cart->(item+i)->itemID), SIZE2);

    cout << "\nEnter #" << i+1 << " price: ";
    cin >> *(cart->(item+i)->price);
    cin.ignore();

    cout << "\nEnter #" << i+1 << " quantity: ";
    cin >> *(cart->itemCount+i);
    cin.ignore();
  }
}