写简易计算器程序代码（C++）

编写一个简单的C++计算器程序，通常包括基本的加、减、乘、除功能，可以按照下面的步骤来实现：

#include <iostream>

// 定义函数，分别代表加、减、乘、除操作
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) {
    if (b != 0)
        return a / b;
    else
        throw std::invalid_argument("Cannot divide by zero.");
}

int main() {
    double num1, num2;
    char operatorSymbol;

    // 用户输入数字和运算符
    std::cout << "Enter the first number: ";
    std::cin >> num1;
    std::cout << "Enter the second number: ";
    std::cin >> num2;
    std::cout << "Choose an operation (+, -, *, /): ";
    std::cin >> operatorSymbol;

    // 根据用户选择调用相应的函数
    switch (operatorSymbol) {
        case '+':
            std::cout << "Result: " << add(num1, num2) << std::endl;
            break;
        case '-':
            std::cout << "Result: " << subtract(num1, num2) << std::endl;
            break;
        case '*':
            std::cout << "Result: " << multiply(num1, num2) << std::endl;
            break;
        case '/':
            try {
                std::cout << "Result: " << divide(num1, num2) << std::endl;
            } catch (const std::invalid_argument& e) {
                std::cerr << e.what() << std::endl;
            }
            break;
        default:
            std::cerr << "Invalid operator! Please choose from (+, -, *, /)." << std::endl;
            break;
    }

    return 0;
}