C++实现简单计算器

注意点：

1. / % 操作符中 第二个操作数不能为0

2. % 操作符 只对整数类型有意义，要把操作数转换成整数，转换完成后检查是否为0.

 

#include
int main()
{
   double number1=0.0;
   double number2=0.0;
   char operation=0;//+-*/ % 

   printf("请输入数字1 操作符 数字二\n");
   scanf("%lf%c%lf",&number1,&operation,&number2);

   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("除数不能为0!\n");
           else
             printf("=%lf\n",number1/number2);
           break;

      case '%':
           if((long)number2==0)  
             printf("无法对零取余\n"); 
           else
             printf("=%ld\n",(long)number1%(long)number2);      
           break;

      default:
          printf("超出运算范围!\n");
          break;          
    }
    return 0;
}