这个程序是关于学生档案管理的,有两个功能,查找和修改,
这个程序运行没有问题,但是我运行后不能进行修改功能,请高手帮忙下!!

#include <stdio.h>
struct student
  {int num;
   char name[10];
   char sex;
   char address[20];
   };
   struct student stu[3]={ {000,"li lin",'m',"103 beijing road"},
               {001,"zhang fun",'m',"130 shanghai road"},
               {002,"wang min",'f',"1010 zhongshan road"}  } ;
   struct student (*p)[3];


void main()
{
void query();
void modify();
char X,Z;
int i;

printf("num    name   sex    address\n");
for (i=0;i<3;i++)
printf("%5d%10s%3c%20s\n",stu[i].num,stu[i].name,stu[i].sex,stu[i].address);


printf("do you want to query?Y OR N\n ");
scanf("%c",&X);
if (X=='Y'||X=='y')
  query();
else if (X=='N'||X=='n')
  printf("byebye!\n");


printf("do you want to modify?Y or N\n");
scanf("%c",&Z);
if (Z=='Y'||Z=='y')
   modify();
else if(Z=='N'||Z=='n')
printf("byebye\n");
}




void query()
{
int i,number;
char Z;
printf("please enter numbers:");
scanf("%d",&number);

printf("num   name   sex   address\n");
for (i=0;i<3;i++ )
{

if (number==stu[i].num)

printf("%3d%20s%2c%20s\n",stu[i].num,stu[i].name,stu[i].sex,stu[i].address);
 }

}





void modify()
{
int modinum,k,i;
printf("please input theseat which you will modify:");
scanf("%d",&modinum);
for (i=0;i<3 ;i++ )
{if (modinum==stu[i].num)
{ k=i;
scanf("%d ",&stu[k].num);
scanf("%s",&stu[k].name);
scanf("%c",&stu[k].sex);
scanf("%s",&stu[k].address);}
}
}

附图,在图中的地方就有问题了 !!!

主要问题:
scanf("%d ",&stu[k].num);
scanf("%s",&stu[k].name);   // 改为 stu[k].name
scanf("%c",&stu[k].sex);
scanf("%s",&stu[k].address); // 改为 stu[k].address

/* 一个修改版本 */

#include <stdio.h>

struct student
{
    int  num;
    char name[10];
    char sex;
    char address[20];
};

struct student stu[3] = {
    {000, "li lin", 'm', "103 beijing road"},
    {001, "zhang fun", 'm', "130 shanghai road"},
    {002, "wang min", 'f', "1010 zhongshan road"}
};

void query(void);
void modify(void);

int main(void)
{
    char ch;
    int i;
   
    printf("num    name   sex    address\n");
    for (i = 0; i < 3; i++)
        printf("%5d%10s%3c%20s\n", stu[i].num, stu[i].name,
                                   stu[i].sex, stu[i].address);
    putchar('\n');

    printf("do you want to query? [Y/N]\n");
    scanf("%c", &ch);
    putchar('\n');
    if(ch != '\n')
        while(getchar() != '\n')
            continue;
    if (ch == 'Y' || ch == 'y')
        query();

    printf("do you want to modify? [Y/N]\n");
    scanf("%c", &ch);
    putchar('\n');
    if(ch != '\n')
        while(getchar() != '\n')
            continue;

    if (ch == 'Y' || ch == 'y')
        modify();

    printf("Bye!\n");
    getchar();
    return 0;
}

void query()
{
    int i, number, k;
   
    printf("please enter numbers: ");
    while(scanf("%d", &number) != 1)
    {
        printf("please enter numbers[integer]: ");
        while(getchar() != '\n')
            continue;
    }
    while(getchar() != '\n')
        continue;

    printf("num    name                sex    address\n");
    for (i = k = 0; i < 3; i++)
    {
        if (number == stu[i].num)
        {
            printf("%-3d    %-20s %c    %20s\n", stu[i].num, stu[i].name,
                                       stu[i].sex, stu[i].address);
            k = 1;
        }
    }
    if(k == 0)
        printf("Not!\n");
   
    putchar('\n');
}

void modify()
{
    int modinum, k, i;
    printf("please input theseat which you will modify:");
    while(scanf("%d", &modinum) != 1)
    {
        printf("please input theseat which you will modify[integer]:");
        while(getchar() != '\n')
            continue;
    }
    while(getchar() != '\n')
        continue;

    for (i = k = 0; i < 3; i++ )
    {
        if (modinum == stu[i].num)
        {
            printf("Please enter num: ");
            while(scanf("%d", &stu[i].num) != 1)
            {
                printf("Please enter num[integer]: ");
                while(getchar() != '\n')
                    continue;
            }
            while(getchar() != '\n')
                continue;

            printf("Please enter name: ");
            while(scanf("%s", stu[i].name) == 0)
            {
                while(getchar() != '\n')
                    continue;
                printf("Please enter name: ");
            }
            while(getchar() != '\n')
                continue;

            do
            {
                printf("Please enter sex[m/f]: ");
                scanf("%c",  &stu[i].sex);
                while(getchar() != '\n')
                    continue;
            }while(stu[i].sex != 'm' && stu[i].sex != 'f');

            printf("Please enter address: ");
            while(scanf("%s",  stu[i].address) == 0)
            {
                printf("Please enter address: ");
                while(getchar() != '\n')
                    continue;
            }
            while(getchar() != '\n')
                continue;
            k = 1;
        }
    }

    if(k == 0)
        printf("Not!\n");

    putchar('\n');
}

非常感谢这位高手!!!

大家说的都没错，当时我也觉得奇怪，就把输入之后的Z和X 输出看了以下，发现第二个字符输出的字符的ascii是10，而且换行的ascii是10，所以我觉得应该是换行的ascii赋给了Z，这样以来就明白了，回车其实占了两个字节的长度包括回车（13）和换行（10），当接收到（13）的时候把前面输入的给了第一个变量，然后自然换行（10）就给了第二个变量，而换行就只输出一个换行，都没注意到，一位没执行！要向避免这个的话也好办，向楼上大家说的那样，我觉得简单的办法是在两个输入之间加入一个getchar（）这样，换行就会被getchar（）接受，在输入也不会有问题，这个方法我亲自试了的，绝对没有问题！谢谢你提出了这么个有价值的问题供 大家研究

getchar() 返回的不可能是 \r ( 13 )。

我是为了去掉缓冲区中多余的字符，并且保证scanf() 可以读取下次的输入。

[[italic] 本帖最后由 cosdos 于 2008-1-3 19:09 编辑 [/italic]]