将循环结果访问到类的实例以进行输出

Question

好的，所以我为我的 C++ 班级分配了班级清单。我现在正在努力解决的问题是循环和对象创建之间的部分。

string description = "";
int id_number{0};
int quantity_number{0};
double price_value{0};

for (int count{1}; count <= inventory_num; count++)
{
    cout << endl;
    cout << "Item #" << count++ << endl;
    cout << "Enter the id number: ";
    cin >> id_number;
    cout << "Descriptiom: ";
    cin.get();
    getline(cin, description);
    cout << "Quantity on hand: ";
    cin >> quantity_number;
    cout << "Unit price: ";
    cin >> price_value;
    cout << endl;

}

InventoryItem item1(id_number, description, quantity_number, price_value);
InventoryItem item2(id_number, description, quantity_number, price_value);
InventoryItem item3(id_number, description, quantity_number, price_value);
InventoryItem item4(id_number, description, quantity_number, price_value);


item1.display(); cout << endl; 
item2.display(); cout << endl;      
item3.display(); cout << endl;
item4.display(); cout << endl;

return EXIT_SUCCESS;
}

所以问题是，例如，循环输入 4 次，但输出只显示所有输出(item1,item2,item3,item4) 的最后一次输入的数据。怎么解决这个小伙子？

Answer 1

您会覆盖每次循环迭代中的值。在循环之后，最后一次迭代的值存储在您的变量中。你可以用 std::vector 修复它

#include "InventoryItem.hpp"
#include <iostream>
#include <string>
#include <vector>
using std::cout;
using std::cin;
using std::endl;
using std::string;
using std::getline;

int main() {
    string description = "";
    int id_number{0};
    int quantity_number{0};
    double price_value{0};
    std::vector<InventoryItem> items;
    for (int count{1}; count <= inventory_num; count++)
    {
        cout << endl;
        cout << "Item #" << count++ << endl;
        cout << "Enter the id number: ";
        cin >> id_number;
        cout << "Descriptiom: ";
        cin.get();
        getline(cin, description);
        cout << "Quantity on hand: ";
        cin >> quantity_number;
        cout << "Unit price: ";
        cin >> price_value;
        cout << endl;
        items.emplace_back(id_number, description, quantity_number, price_value);
    }

    items[0].display(); cout << endl; 
    items[1].display(); cout << endl;      
    items[2].display(); cout << endl;
    items[3].display(); cout << endl;

    return EXIT_SUCCESS;
}