fflush 清除文件缓冲区

出自：http://baike.baidu.com/view/656650.htm

fflush(stdin)

 1 #include <stdio.h>
 2 int main()
 3 {
 4   int num1,num2;
 5   char flag;
 6   while(1)
 7   {
 8     printf("Please input  num1:");
 9     scanf("%d",&num1);
10     printf("Please input  num2:");
11     scanf("%d",&num2);
12     printf("%d+%d=%d
",num1,num2,num1+num2);
13     printf("Continue?[Y/N]");
14     fflush(stdin);
15     scanf("%c",&flag);
16     if(flag=='N'||flag=='n')
17     {
18       break;
19     }
20   }
21   printf("Press any key to continue...");
22   fflush(stdin);
23   getchar();
24   return 0;
25 }