实现加减乘除计算。

实例

# 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;

}

输出结果为：

输入操作符 (+, -, *,): *输入两个数字: 4 54.0 * 5.0 = 20.0