C++ 程序在运行时重新使用变量或创建变量？

Question

无论如何，您是否可以将数据存储在 C++ 控制台应用程序中，将其传输到不同的变量，然后重用该变量？

为什么我想要这个:我想让用户输入订单的订单详细信息，然后让程序能够存储它们，以便程序可以重新创建另一个订单。

当前代码:

int quant;
int cost;
int selling;
int profit;
    NewOrder:
cout <<""<< endl;
cout << "Enter an Order Number: " << flush;
getline(cin, ord);

cout << "Enter a Product ID: " << flush;
getline(cin, Prod);

cout << "Enter a Quantity: " << flush;
cin>>quant;
          Pricing:
cout << "Enter a cost per unit: " <<char(156) << flush;
cin >> cost;

cout << "Enter a selling price per unit: " <<char(156) << flush;
cin >> selling;

Sleep(2000);
cout << endl;
cout << "Your order Details are:" << endl;
cout << "Order Number: " << ord << endl;
cout << "Product: " <<Prod << endl;
cout << "Quantity:" << quant << endl;
cout << "Total Cost: " <<char(156) << (quant*cost) << endl;
cout << "Total Selling Price: " <<char(156)<< (quant*selling) << endl;

profit = ((quant*selling) - (quant*cost)); //Assigning a value to profit.

cout << "Total Profit: " <<char(156)<< profit << endl;
if (profit < 0) { 
    cout << "You have a negative profit. Please change your pricing." << endl;
    Sleep(3000);
    goto Pricing; } 

目前，它允许用户输入一个订单的详细信息，然后显示它们。我想要它，这样程序就可以输入多个订单，然后按订单号可以召回它们。我可以使用程序内存来​​执行此操作还是需要将其设置为 SQL DB？

如果是这样，我该如何设置 SQL 连接？

如果我可以在内存中完成，怎么做？我一直在四处寻找，但无法在运行时创建和声明变量。

Answer 1

您可以使用 vector 跟踪所有订单:

struct Product {
    //Add additional fields you need here
    int quant;
    int cost;
    int selling;
    int profit;
};

int main() {
    std::vector<Product> products;

    while (stillAddingProducts) {
        //Get all the data from the user
        Product p;
        p.quant = 10; //example you should get this from the user

        //Insert the product based on the information received
        products.push_back(p);
    }

    //Perhaps iterate through all products and display information
    for (const auto& e : products) {
        std::cout << "Quantity: " << e.quant << std::endl;
    }
}

有了这个，您将在每次迭代中拥有一个“全新”的 Product 对象。在旁注中，尝试 avoid在您的代码中使用 goto。