以下是我自己写的一个简单的小小计算器，只能计算简单加减乘除，我预想中出现的结果应该是：
choose +, -, *, /:+
First number:     6
Second number:    3
Answer:   6 + 3 = 9

choose +, -, *, /:

为什么实际上运行时，出现的结果却是：
choose +, -, *, /:+
First number:     6
Second number:    3
Answer:   6 + 3 = 9

choose +, -, *, /:
Error:Only +, -, *, / are available.Try again!   (注明：为什么就多了这一行呢？这不是我想要的结果啊！原因何在？我总感觉是，当我输入第二个数字3的时候，按下回车键后，回车键的输入值被运用到了  printf("Choose +, -, *, or /:\t");  
                                    scanf("%c", &operator);
                                                                      这两个个语句上，求高人给指点指点！)

以下是我自己写的一个雏形代码，估计有点难看！初学者，还望不要见笑：

#include<stdio.h>

int main ( void )
{
    long a, b;
    char operator;
    long answer;  
   
    while (1)
    {
          printf("Choose +, -, *, or /:\t");
          scanf("%c", &operator);      
         
          switch (operator)
          {              
                       
                 case '+':     
                      {
                          printf("First number:\t\t");
                          scanf("%ld", &a);
                          printf("Second number:\t\t");
                          scanf("%ld", &b);
                          printf("Answer:\t\t%ld %c %ld = %ld\n\n\n", a, operator, b, a+b);
                          break;
                      }  
                 case '-':
                      {
                          printf("First number:\t\t");
                          scanf("%ld", &a);
                          printf("Second number:\t\t");
                          scanf("%ld", &b);
                          printf("Answer:\t%ld %c %ld = %ld\n\n\n", a, operator, b, a-b);
                          break;
                      }
                 case '*':  
                      {
                          printf("First number:\t\t");
                          scanf("%ld", &a);
                          printf("Second number:\t\t");
                          scanf("%ld", &b);
                          printf("Answer:\t%ld %c %ld = %ld\n\n\n", a, operator, b, a*b);
                          break;
                      }
                 case '/':
                      {
                          printf("First number:\t\t");
                          scanf("%ld", &a);
                          printf("Second number:\t\t");
                          scanf("%ld", &b);
                          printf("Answer:\t%ld %c %ld = %ld\n\n\n", a, operator, b, a/b);
                          break;
                      }                                         
                 default:
                         {
                             printf("\nError: Only +, -, *, / are available. Try again!\n\n\n");
                         }
                        
                           
          } /*End of switch */
                     
    }  /* End of while */
}

话说 增加一个getchar 用来吸收你多敲的 回车 键

    } /*End of switch */
          getchar();
                    
    }  /* End of while */
} 

另外 你的是啥编译器啊

 char operator ;  这句在vs2010里不可编译

收到的鲜花

• 小青龙 于 2013-08-02 13:29 送鲜花  3朵   附言：我很赞同

高端啊
VS2010
我还是08咧

   哎呀  不知道08啥样啊  2010实在是消耗资源啊  太庞大了

加个清空键盘缓冲区的函数试试，感觉这是比较常见的解决办法

fflush(stdin);

把它加到合适位置(接收想要的键盘输入字符之前)就可以了

收到的鲜花

• 小青龙 于 2013-08-02 13:29 送鲜花  3朵   附言：我很赞同

让我这个手一抖，

在C盘里装了VS2012的情何以堪呐~

放到vc++中一大堆错误啊！类型不明确
。。

我目前用的是DEV-C + +，因为之前对c几乎不了解，就随便用了个。

谢谢解答！像我这样的初学者，还是自学者，每走一步，估计都是荆棘满路。

另外有一疑问：初学者，用什么编译器好？用高端的好？还是……？