//定义一个结构体变量（包括年、月、日），写一个days函数实现计算是一年中的第几天？由函数将年、月、日传递给days函数，计算后将日子数传回主函数输出

#include<stdio.h>
struct dayss //这是定义结构体变量
{
int y;
int m;
int d;
}di;
int days(struct dayss di) //这是计算一年当中第几天的函数
{
int day[2][12]={{31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31},{31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}};
int leap,i;
if((di.y%4==0 && di.y%100!=0) || (di.y%400==0))
leap=1;
else
leap=0;
for(i=0;i<di.m-1;i++)
di.d+=day[leap][i];
return di.d; //最后返回一年当中第几天的值
}
void main()
{
struct dayss di;
int days;
printf("请输入年份:");
scanf("%d",&di.y);
printf("请输入月份:");
scanf("%d",&di.m);
printf("请输入天数:");
scanf("%d",&di.d);
days=days(di); //调用函数

printf("%d年%d月%d日是一年当中第%d",di.y,di.m,di.d,days);
}





C:\Documents and Settings\英雄\桌面\aaa\Cpp1.cpp(30) : error C2064: term does not evaluate to a function
Error executing cl.exe.

Cpp1.exe - 1 error(s), 0 warning(s)

void main()
{
struct dayss di;
int days;
printf("请输入年份:");
scanf("%d",&di.y);
printf("请输入月份:");
scanf("%d",&di.m);
printf("请输入天数:");
scanf("%d",&di.d);
days=days(di); //调用函数

printf("%d年%d月%d日是一年当中第%d",di.y,di.m,di.d,days);
}

看见这三个红色的days没有？因为你定义的变量的调用的函数名相同，所以编译器无法识别清楚．把这个变量改成其他名字就ＯＫ了｀｀

#include<stdio.h>
struct dayss //这是定义结构体变量
{
int y;
int m;
int d;
}di;
int days(struct dayss di) //这是计算一年当中第几天的函数
{
int day[2][12]={{31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31},{31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}};
int leap,i;
if((di.y%4==0 && di.y%100!=0) || (di.y%400==0))
leap=1;
else
leap=0;
for(i=0;i<di.m-1;i++)
di.d+=day[leap][i];
return di.d; //最后返回一年当中第几天的值
}
void main()
{
struct dayss di;
int days; /*这个变量名，与您的函数名重复，改一下就可以了。*/
printf("请输入年份:");
scanf("%d",&di.y);
printf("请输入月份:");
scanf("%d",&di.m);
printf("请输入天数:");
scanf("%d",&di.d);
days=days(di); //调用函数

printf("%d年%d月%d日是一年当中第%d",di.y,di.m,di.d,days);
}