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这是我的主要内容：

int main() {
  Inventory Master;
  bool flag;
  Customer Bob("Bob", "CreditCard.txt");
  Customer Joe("Joe", "CreditCard.txt" );



  Master.firststock( "inventory.txt" );
  vector<Food> temp = Master._Inv;
  cout <<"Hi, What would you like to buy today?" << endl;
  for(unsigned int i=0; i<temp.size(); i++ ) {
    cout << temp[i].name << " " << temp[i].quant << " " << temp[i].price << endl;
  }

  cout <<"\n";
  Food Apple("Apples", .99, 10);
  Food Orange("Oranges", .99, 10);
  Food Chip("Chips", 3.00, 10);

  cout <<"\nHi Bob" << endl;
  flag = Bob.addCart(Apple, 7, &Master);
  cout <<"Bob's total purchases are Currently: \n";
  Bob.report();
  flag = Bob.addCart(Orange, 2, &Master);
  flag = Bob.addCart(Chip, 2, &Master);
  Bob.report();
  flag = Bob.removeCart();
   Bob.report();
  cout <<"Bob, ";
  flag = Bob.checkout(&Master);

这是我为从矢量_Cart 中移除食物而实施的以下操作：

bool Customer::removeCart() {
  bool flag;
  int q = 0;
  unsigned int i=0;
  string remove;

  cout << "\nWhat would you like to remove and how much would you like to remove?" << endl;
  cin >> remove >> q;
 for (i =0; i < _Cart.size(); i++) {
  if(remove == _Cart[i].name) {
      if (q >= 0) {
    _Cart[i].quant -= q;
    //inv->_Inv[i].quant += q;
    cout <<"\nYou removed " << q << " " << remove <<" In your cart\n" << endl;
    return true;
      }
      if  (q < 0) {
          cout << "Invalid number of " << remove << " being removed.\n" << endl;
          return true;
      }
  }
  else {      
  try {
    throw remove;
}

  catch (string param) {
    cout << "\n" << remove << " doesn't exist in your cart\n" << endl;
        }

        return true;
    }
 }

我的标题包含函数 removeCart：

class Customer {
  public:

   Customer(string n, string fileName);
    ~Customer() { _Cart.clear(); };
    bool addCart(Food f, int q, Inventory* inv);
    bool removeCart();
    void report(); 
    bool checkout(Inventory* inv); 
  protected:
    string remove;
    string name;
    int q;
    int card;
    double balance;
    CreditCard _CC(int card,double balance);
    vector<Food> _Cart;
};

现在由于某种原因，当我调用 removeCart 时，输入“Apples”有效，但我注意到我制作了一个名为 Apple 的食物对象，所以不知道为什么输入“Apples”而不是“Apple”可以删除。此外，当我尝试“Orange”或“Chip”时，会显示异常，但正如您在 main 中看到的那样，我将 Chip 和 Orange 添加到 Bob 的购物车中。我什至尝试过“Oranges”和“Chips”，但它仍然给我抛出异常而不是工作。我很感激帮助。

4

2 回答 2

0

您的 for/if/else 结构已损坏。如果您不匹配购物车中的第一个元素，则会引发异常，您会立即捕获该异常。尝试更多类似的东西：

 for (i =0; i < _Cart.size(); i++)
 {
    if(remove == _Cart[i].name)
    {
        if (q >= 0)
        {
           _Cart[i].quant -= q;
           //inv->_Inv[i].quant += q;
           cout <<"\nYou removed " << q << " " << remove <<" In your cart\n" << endl;
        }
        else
           cout << "Invalid number of " << remove << " being removed.\n" << endl;
        return true;
    }
 }
 cout << "\n" << remove << " doesn't exist in your cart\n" << endl;
 return true;
于 2012-08-07T06:11:52.310 回答
0

是家庭作业吗？:)

首先，“Apple”是您创建的变量的名称，但是您将“Apples”传递给 Food 的构造函数，所以我认为这个值被分配给它的“name”成员，用于比较。

其次，正如大卫注意到的那样，只有当您尝试删除购物车中的第一个元素时，您的循环才会起作用。在您的情况下，第一个元素被命名为“Apples”，因此输入“Apples”有效。

于 2012-08-07T06:19:19.957 回答