c++可进行四则运算的程序

在C++中，编写一个简单的四则运算程序，你可以创建一个包含加法、减法、乘法和除法函数的类，并提供一个用户界面让使用者输入操作数和选择运算符。下面是一个基础的示例：

#include <iostream>
using namespace std;

class Calculator {
public:
    double add(double a, double b) { return a + b; }
    double subtract(double a, double b) { return a - b; }
    double multiply(double a, double b) { return a * b; }
    double divide(double a, double b) { // 检查除数是否为零
        if (b != 0)
            return a / b;
        else
            throw "Error: Division by zero is not allowed!";
    }

    void performOperation() {
        double num1, num2;
        char operatorChoice;

        cout << "Enter first number: ";
        cin >> num1;
        cout << "Enter second number: ";
        cin >> num2;
        cout << "Choose an operation (+, -, *, /): ";
        cin >> operatorChoice;

        switch (operatorChoice) {
            case '+':
                cout << "Result: " << add(num1, num2) << endl;
                break;
            case '-':
                cout << "Result: " << subtract(num1, num2) << endl;
                break;
            case '*':
                cout << "Result: " << multiply(num1, num2) << endl;
                break;
            case '/':
                try {
                    cout << "Result: " << divide(num1, num2) << endl;
                } catch (const char* msg) {
                    cerr << msg << endl;
                }
                break;
            default:
                cerr << "Invalid choice! Please enter a valid operator." << endl;
                break;
        }
    }
};

int main() {
    Calculator calc;
    calc.performOperation();
    return 0;
}