Question

我可以向用户显示程序菜单，但是我无法执行实际的数学运算。例如，当我输入2时，它仅显示0，而不是让我输入两个整数，然后将它们相乘或相加。如何获得允许用户输入1、2或3的选项，然后让其执行他们输入的操作？

#include <iostream>

using namespace std;

    int main()
    {
    int choice;
    int numberOne = 0;
    int numberTwo = 0;
    int sumOfTwoNumbers = 0;
    int productOfTwoNumbers = 0;

    do{
        cout <<"Please select one of the following options:  \n";

        cout << "1: Enter two integer values\n"
        "2: Add the two values\n"
        "3: Multiply the two values\n"
        "4: Exit\n";

        cout << "Enter your selection (1, 2,3 or 4): ";
        std::cin >> choice;

            switch (choice)
            {
            case 1:
                cout << "Enter two integer values. " << endl;
                cin >> numberOne >> numberTwo;
                break;

            case 2:
                sumOfTwoNumbers = numberOne + numberTwo;
                cout << sumOfTwoNumbers << endl;
                break;

            case 3:
                productOfTwoNumbers = numberOne * numberTwo;
                cout << productOfTwoNumbers << endl;
                break;

            case 4:
                cout << "You have chosen Exit, Goodbye.";
                break;

            default:
                cout<< "Your selection must be between 1 and 4!\n";
                break;

          }

    }while(choice!= '4');

    return 0;

}

Answer 1

在情况1中，您只要求提供两个数字。在其他选项中，数字保留为默认值0。无论选择哪个选项，都需要确保分配两个数字。另外，您的案例没有多大意义，因为所有选项都需要输入两个数字。我删除了情况1，只需移动行

cout << "Enter two integer values. " << endl;
cin >> numberOne >> numberTwo;

在switch语句上方：

cout <<"Please select one of the following options:  \n";

cout << 
"1: Add the two values\n"
"2: Multiply the two values\n"
"3: Exit\n";

cout << "Enter your selection (1, 2, or 3): ";
std::cin >> choice;
cout << "Enter two integer values. " << endl;
cin >> numberOne >> numberTwo;
switch (choice)
{
   case 1:
      sumOfTwoNumbers = numberOne + numberTwo;
      cout << sumOfTwoNumbers << endl;
      break;
   case 2:
      //etc

使用do while和switch的C ++程序菜单

1 个答案: