struct Date{
    int month;
    int day;
    int year;
};
struct Person{
    char name[20];
    char sex;
    struct Date birthday;
    unsigned long num;        /*身份证号码*/
};
#include <stdio.h>
int main(void)
{
    struct Person p1={"wanglin",'M',12,15,1974,111000222};
    struct Person p2;
    p2.name[6]="wenya";    /*这里如果我需要单独赋值，应该怎样呢？我这里是错误的*/
    p2.sex='W';
    p2.num=111000223;
    p2.birthday=p1.birthday;
    printf("Person1: %s, %c, %d-%d-%d, %lu\n",p1.name,p1.sex,p1.birthday.month,p1.birthday.day,p1.birthday.year,p1.num);
    printf("Person2: %s, %c, %d-%d-%d ,%lu\n",p2.name,p2.sex,p2.birthday.month,p2.birthday.day,p2.birthday.year,p2.num);
    return 0;
}

问题在注释里，谢谢了～

p2


在哪里定义的？

改成用指针吧 char[]   我也没搞懂呢


struct Date{
    int month;
    int day;
    int year;
};
struct Person{
    char* name;
    char sex;
    struct Date birthday;
    unsigned long num;      
};
#include <stdio.h>
int main(void)
{
    struct Person p1={"wanglin",'M',12,15,1974,111000222};
    struct Person p2;
    p2.name = "alibaba";
    p2.sex='W';
    p2.num=111000223;
    p2.birthday=p1.birthday;
    printf("Person1: %s, %c, %d-%d-%d, %lu\n",p1.name,p1.sex,p1.birthday.month,p1.birthday.day,p1.birthday.year,p1.num);
    printf("Person2: %s, %c, %d-%d-%d ,%lu\n",p2.name,p2.sex,p2.birthday.month,p2.birthday.day,p2.birthday.year,p2.num);
   
    return 0;
}

刚试的：

char name[20];

把 p2.name = "alibaba"; 改成   
strcpy(p2.name,"alibaba");  -- 把“alibaba" 复制到p2.name

p2.name[6]="wenya";   
p2.name[6]是数组，而数组是不能整体赋值的。具体的办法是1）使用strcpy函数
2）在结构体声明中将name【6】改为char *name。