Question

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);

以下是我实施的以从我的矢量中删除食物_Cart：

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，当我打电话给removeCart时，输入“苹果”有效，但我注意到我做了一个名为Apple的食物对象，因此不确定为什么键入“苹果”可以用于删除而不是“Apple”。此外，当我尝试“橙色”或“芯片”时，会显示例外情况，但正如您在主要内容中所看到的，我将芯片和橙色添加到Bob的购物车中。我甚至尝试过“橘子”和“筹码”，它仍然让我失去了异常，而不是工作。我很感激你的帮助。

Answer 1

您的for / if / else结构已损坏。如果您对购物车中的第一个元素不匹配，则会抛出异常，您会立即捕获该异常。尝试更像这样的东西：

 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;

Answer 2

这是作业吗？：）

首先，“Apple”是你创建的变量的名称，但是你将“Apples”传递给Food的构造函数，所以我想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，第一个元素名为“Apples”，因此输入“Apples”可以正常工作。

去除食物中的食物，但某些食物没有去除？为什么

2 个答案: