#include "stdio.h"
void main()
{
    int n1,n2;
    char a;
    printf("请按顺序输入两个数字和运算符\n");
    scanf("%f，%f",&n1,&n2);
    switch(a)
    {
        case'+':result=n1+n2;
            break;
        case'-':result=n1-n2;
            break;
        case'*':result=n1*n2;
            break;
        case'/':if(n2==0)
                    printf("输入的数字非法，请从新输入");
                else
                    result=n1/n2;
            break;
        default:printf("运算符非法");
    }
    printf("%.2c",result);

}

上面是代码。一直出现问题。各位大神看看，求解！