Question

目前我正在尝试编写自动售货机程序，而我似乎有两个逻辑错误，我无法弄清楚。首先，当我尝试为我的自动售货机程序选择不同的产品时，它总是选择第一个产品而我不知道为什么。其次，我试图让退出条件允许用户随时退出程序，但程序总是在我询问用户后无论如何都会结束。以下是我的代码：

//Vending Machine Program
#include <iostream>;
using namespace std;

int main()
{
    double product1 = 59.99;
    double product2 = 59.99;
    double product3 = 59.99;
    double product4 = 59.99;
    double customerMoney = 0.00;

    cout << "How much money do you have? ";
    cin >> customerMoney;

    while (customerMoney >= 59.99)
    {
        int customerChoice = 0;
        //bool exitProgram;

        cout << "Which product would you like to buy?\n Enter '1' for Killzone: Shadow Fall ($59.99)\n Enter '2' for Deadrising 3 ($59.99)\n Enter '3' for Call of Duty Ghosts ($59.99)\n Enter '4' for Madden NFL 25 ($59.99)";
        cin >> customerChoice;
        if (customerChoice = 1)
        {
            cout << "You have selected Killzone: Shadow Fall\n";
            customerMoney = customerMoney - product1;
            cout << "You have $" << customerMoney << " left\n";

            /*cout << "Would you like to exit the program? (Enter '1' for true and '0' for false)";
            cin >> exitProgram;
            if (exitProgram = 1)
            {
                return 0;
            }*/
        }
        else if (customerChoice = 2)
        {
            cout << "You have selected Deadrising 3\n";
            customerMoney = customerMoney - product2;
            cout << "You have $" << customerMoney << " left\n";

            /*cout << "Would you like to exit the program? (Enter '1' for true and '0' for false)";
            cin >> exitProgram;
            if (exitProgram = 1)
            {
            return 0;
            }*/
        }
        else if (customerChoice = 3)
        {
            cout << "You have selected Call of Duty Ghosts\n";
            customerMoney = customerMoney - product3;
            cout << "You have $" << customerMoney << " left\n";

            /*cout << "Would you like to exit the program? (Enter '1' for true and '0' for false)";
            cin >> exitProgram;
            if (exitProgram = 1)
            {
            return 0;
            }*/
        }
        else if (customerChoice = 4)
        {
            cout << "You have selected Madden NFL 25\n";
            customerMoney = customerMoney - product4;
            cout << "You have $" << customerMoney << " left\n";

            /*cout << "Would you like to exit the program? (Enter '1' for true and '0' for false)";
            cin >> exitProgram;
            if (exitProgram = 1)
            {
            return 0;
            }*/
        }
        else
        {
            cout << "You don't have enough money to purchase anything else. Thank you for shopping!";
        }
    }

    cin.get();
    return 0;
}

Answer 1

if (customerChoice = 1)

您正在使用“=”这是一个分配。你需要“==”

if (customerChoice == 1)

这不会引发编译错误的原因是从技术上讲，分配确实会返回一个值。事实上，在您的情况下，为customerChoice分配1的返回值将为1，这将在if语句中评估为True。

自动售货机计划（帮助）

1 个答案: