STUDENT *change(STUDENT *head)
{
STUDENT *f=NULL,p=NULL;
p=head;
int x;
if(head!=NULL)
{
printf("请输入需要修改的学生的学号");
scanf("%-15ld",&f->num);
while(p!=NULL)
{
if(f->num==p->num)
{
scanf("%d",&x);
switch(x)
{
case 1:
p->num=f->num;
case 2:
scanf("%s",&f->name);
strcpy(p->name,f->name);
case 3:
scanf("%s",&f->phone);
p->phone=f->phone;
}
break;
}
else
{
printf("t抱歉,没有学生数据!");
break;
}
p=p->next;
}
}
}
一直不进去while循环