C 语言实例 - 实现简单的计算器

实现加减乘除计算。

# include <stdio.h>

int main() {

char operator;

    double firstNumber,secondNumber;

    printf("输入操作符 (+, -, *,): ");

    scanf("%c", &operator);

    printf("输入两个数字: ");

    scanf("%lf %lf",&firstNumber, &secondNumber);

    switch(operator)

{

case '+':

            printf("%.1lf + %.1lf = %.1lf",firstNumber, secondNumber, firstNumber + secondNumber);

            break;

        case '-':

            printf("%.1lf - %.1lf = %.1lf",firstNumber, secondNumber, firstNumber - secondNumber);

            break;

        case '*':

            printf("%.1lf * %.1lf = %.1lf",firstNumber, secondNumber, firstNumber * secondNumber);

            break;

        case '/':

            printf("%.1lf / %.1lf = %.1lf",firstNumber, secondNumber, firstNumber / secondNumber);

            break;

        // operator doesn't match any case constant (+, -, *, /)

default:

            printf("Error! operator is not correct");

    }

return 0;

}