简易计算器C语言代码

在C语言中编写一个简单的计算器程序，通常涉及到基本的算术运算如加、减、乘、除。下面是一个基础的命令行计算器的简单示例：

#include <stdio.h>

// 定义计算函数
int add(int a, int b) {
    return a + b;
}

int subtract(int a, int b) {
    return a - b;
}

int multiply(int a, int b) {
    return a * b;
}

int divide(int a, int b) {
    if (b != 0) {
        return a / b;
    } else {
        printf("Error: Division by zero is not allowed.\n");
        return 0; // 或者抛出异常，这里简化为返回0
    }
}

int main() {
    int choice, num1, num2;

    printf("Select operation:\n");
    printf("1. Add\n");
    printf("2. Subtract\n");
    printf("3. Multiply\n");
    printf("4. Divide\n");
    scanf("%d", &choice);

    printf("Enter two numbers: ");
    scanf("%d %d", &num1, &num2);

    switch (choice) {
        case 1:
            printf("Result: %d\n", add(num1, num2));
            break;
        case 2:
            printf("Result: %d\n", subtract(num1, num2));
            break;
        case 3:
            printf("Result: %d\n", multiply(num1, num2));
            break;
        case 4:
            printf("Result: %d\n", divide(num1, num2));
            break;
        default:
            printf("Invalid choice. Please try again.\n");
            return 1;
    }

    return 0;
}