C语言实现加减乘除四则运算（小数）

雨点打透心脏的1/2处 2022-08-07 10:46 269阅读 0赞

没什么可说的，很简单，写出加减乘除函数，在用switch....case语句调用就行了；

代码实现如下：

#include<stdio.h>
    
    float add(float a,float b)
    {
    	return a+b;
    }
    float sub(float a,float b)
    {
    	return a-b;
    }
    float mul(float a,float b)
    {
    	
    	return a*b;
    }
    float div(float a,float b)
    {
    	
    	return a/b;
    }                                                               //加减乘除函数
    int main()
    {
    	float a,b;
    	int n = 1;
        float ret = 0;
     A:	printf("****************************\n");
    	printf("          1.add             \n");
    	printf("          2.sub             \n");
    	printf("          3.mul             \n");
    	printf("          4.div             \n");
    	printf("          0.goodbye         \n");
    	printf("****************************\n");               //选择表
    	while(n)
    	{
    		printf("please input:\n");
    		scanf("%d",&n);
    		switch(n)
    		{
    		case 1:
    			printf("please input:\n");
    			scanf("%f %f",&a,&b);
    			ret = add(a,b);                           //定义一个变量接收返回值
    			break;
    		case 2:
    			printf("please input:\n");
    			scanf("%f %f",&a,&b);
    			ret = sub(a,b);
    			break;
    		case 3:
    			printf("please input:\n");
    			scanf("%f %f",&a,&b);
    			ret = mul(a,b);
    			break;
    		case 4:
    			printf("please input:\n");
    			scanf("%f %f",&a,&b);
    			ret = div(a,b);
    			break;
    		case 0:
    			printf("-----see you!-----\n");                   //退出
    			return 0;
    		default:
    			printf("please input again:\n");
    			break;
    		}
    		printf("ret = %f\n",ret);
    		goto A;                                 //返回选择表
    	}
    	
    	return 0;
    }

结果如下：

加法实现

![Center][]

减法实现：

![Center 1][]

乘法实现：

![Center 2][]

除法实现：

![Center 3][]

[Center]: /images/20220805/43d9e76701a142db8c73e0232a7be665.png
[Center 1]: /images/20220805/d47b8251518e434dad4bd1b83ae0c947.png
[Center 2]: /images/20220805/c5b61317d2b942b4a3f05051bcb542c3.png
[Center 3]: /images/20220805/489b5955d67b487b814608574d5db940.png