Ceteris paribus(格式良好的数据,良好的缓冲实践和什么不是),是否有一个原因,为什么我喜欢循环,而scanf的返回是1,而不是！EOF？我可能已经读过这个地方,或者什么,但是我也可能错了.别人怎么想？
解决方法
scanf返回成功转换的项目数…或EOF出错.所以编写条件是有道理的.
scanfresult = scanf(...); while (scanfresult != EOF) /* while scanf didn't error */ while (scanfresult == 1) /* while scanf performed 1 assignment */ while (scanfresult > 2) /* while scanf performed 3 or more assignments */
有争议的例子
scanfresult = scanf("%d",&a);
/* type "forty two" */
if (scanfresult != EOF) /* not scanf error; runs,but `a` hasn't been assigned */;
if (scanfresult != 1) /* `a` hasn't been assigned */;
编辑：添加另一个更有创意的例子
int a[5],b[5];
printf("Enter up to 5 pairs of numbers\n");
scanfresult = scanf("%d%d%d%d%d%d%d%d%d%d",a+0,b+0,a+1,b+1,a+2,b+2,a+3,b+3,a+4,b+4);
switch (scanfresult) {
case EOF: assert(0 && "this didn't happen"); break;
case 1: case 3: case 5: case 7: case 9:
printf("I said **pairs of numbers**\n");
break;
case 0:
printf("What am I supposed to do with no numbers?\n");
break;
default:
pairs = scanfresult / 2;
dealwithpairs(a,b,pairs);
break;
}
