C语言下的简易计算器

 #include <stdio.h>
 #include <math.h>
 int main()
 {
     double data1, data2;
     char op;
     while ( == scanf("%lf%c%lf", &data1, &op, &data2) )
         {
             double result;
             printf("%lf%c%lf=", data1,data2);
             switch (op)
             {
                 case '+':
                 result = data1 + data2;
                 break;
                 case '-':
                 result = data1 - data2;
                 break;
                 case '*':
                 result = data1 * data2;
                 break;
                 case '/':
                 result = data1 / data2;
                 break;
                 default:;
             }
             printf("%lf\n", result);
         }    

     return ;
 }

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说明：上面的代码在计算特定运算时会出现舍入错误，原因待定，修改代码如下解决。

 #include <stdio.h>
 int main()
 {
     float data1, data2;
     char op;
     while ( == scanf("%f%c%f", &data1, &op, &data2) )
         {
             float result;
             printf("%f%c%f=", data1, op, data2);

             switch (op)
             {
                 case '+':
                 result = data1 + data2;
                 break;
                 case '-':
                 result = data1 - data2;
                 break;
                 case '*':
                 result = data1 * data2;
                 break;
                 case '/':
                 result = data1 / data2;
                 break;
                 default:;
             }
             printf("%f\n", result);
         }    

     return ;
 }