// 简单四则运算计算器
#include<stdlib.h>
#include<stdio.h>
int main()
{
    there:
    double number1 = 0.0;           //初始化被除数
    double number2 = 0.0;           //初始化除数
    char operation = '0';
     printf("\n输入算式\n");
     scanf("%lf%c%lf",&number1,&operation,&number2);        //输入符合规定的算式

     /*检查输入的运算符号*/
     switch(operation)
     {
         case '+':
             printf("= %lf\n",number1 + number2);
             break;
         case '-':
            printf("= %lf\n",number1 - number2);
            break;
        case '*':
             printf("= %lf\n",number1 * number2);
             break;
        case '/':
             if(number2 == 0)
                 printf("\n\n除数不能为零！");
             else
                printf("= %lf\n",number1 / number2);
            break;
        case '%':
              if((long)number2 == 0)
                printf("\n\n除数不能为零！!");
              else
                 printf("= %ld\n",(long)number1 % (long)number2);
              break;

        default:
            printf("\n\n非法操作！");
            break;
     }
     fflush(stdin);
     char con;
     printf("\n继续运算？ Y or N \n");
         if((con = getchar()) == 'y'||'Y')
             goto there;
         else
          if((con = getchar()) == 'n'||'N')
             exit(0);
return 0;
}      



输入n之后却无法退出程序，求救

小试了下  'y'||'Y'和 'n'||'N'把后面的||‘Y’和‘N’去掉就可以了  原因不是很清楚

"=="的优先级要高于"||",

不论是'Y'还是'N',和你输入的任意字符进行"||"运算都是为真,所以程序不退出.  

加个括号,将代码改一下就可以了:

if((con = getchar()) == ('y'||'Y'))

 if((con = getchar()) ==( 'n'||'N'))

收到的鲜花

• a631908999 于 2014-05-21 23:16 送鲜花  1朵   附言：我很赞同

输入判断有误

3Q