如何将枚举值分配给用户定义的双精度变量？ C ++

Question

您好，我是一名学生，所以我想对不起，以防我的论文累人，请随时纠正我。

我遇到以下问题，我试图将一个枚举int值分配给另一个双精度变量以进行一个乘法。 因此变量costOfRoom应该采用属于枚举的值D或T或S。 （D = 200，T = 150，S = 110）

这必须由用户完成。

但是找不到任何方法，我试图将第二个变量设置为字符串类型，但无法再次使用。 它只会像字符串一样正常使用chars :(

还尝试了cin >> type_Ofroom costofroom ; 但我认为这是在Java中使用的？

在论坛上搜索也没有任何类似的答案:(

该程序运行良好，没有任何编译错误:)

谢谢你的时间

/* build a software system which will allow a hotel receptionist,
to enter in bookings for guests who come to the desk.
The system should display the room options as:
Room        Price       Code
---------------------------------------------------------------
Deluxe Room £200         D
Twin Room       £150     T
Single      £110         S

The receptionist should be prompted to enter in the room type and the number of 
nights a guest wishes to stay for and then calculate the amount
they need to pay. 
   */

// solution 
#include <iostream>
using namespace std;
int main() {

    // decleration of variables 
    double number_OfDays = 0, Totalcost = 0, costofroom = 0;
    enum   type_Ofroom { D = 200, T = 150, S = 150 };
    cout << "enter the type of the room " << endl << endl;

    //input of room type
    cin >> costofroom; // **here is the problem**  i am trying to give the 
                       //    values of the enum varaiable 
                        // it should have D or T or S but i cant  make it
    cout << "enter the number of the days " << endl << endl;

    //input of days
    cin >> number_OfDays;

    // calculation 
    Totalcost = costofroom * number_OfDays;

    // result 
    cout << "the costumer has to pay " << Totalcost << " pounds" << endl << endl;
    return 0;
}

Answer 1

您可以读入double ，然后对照您的enum值进行检查：

//input of room type
while (1)
{
    cin >> costofroom;
    if (costofroom == 0.0)
        costofroom = D;
    else if (costofroom == 1.0)
        costofroom = T;
    else if (costofroom == 2.0)
        costofroom = S;
    else
    {
        cout << "You didn't enter a valid option" << endl;
        continue;
    }
    break;
}

但是，最好将其读入int ，然后再设置double 。

double costofroom;
int option;

...

//input of room type
while (1)
{
    cin >> option;
    if (option == 0)
        costofroom = D;
    else if (option == 1)
        costofroom = T;
    else if (option == 2)
        costofroom = S;
    else
    {
        cout << "You didn't enter a valid option" << endl;
        continue;
    }
    break;
}

Answer 2

用户只能输入字符。 cin会将数字分组转换为int（例如123）或double（例如123.5）。 它还将处理非数字分组为std :: strings（例如，hello）或单个字符（例如，c）。

输入用户的输入后，可以将其转换为枚举。 您可以使用if语句，case语句或某种类型的表进行查找。