#include <iostream>
using namespace std;
struct Date
{int month;
int day;
int year;
};
struct Student
{int num;
char name [20];
char sex;
Date birthday;
float score;
}student 1,student 2={10002,"wang li",'f',5,23,1992,89.5};
int main( )
{student1=student2;
cout<<student1.num<<endl;
cout<<student1.name<<endl;
cout<<student1.sex<<endl;
cout<<student1.birthday.month<<'/'<<student.birthday.day<<'/'<<student1.birthdayyear<<endl;
cout<<student1.score<<endl;
return 0;
}

看不懂你这东东  一会student 1 一会student1  搞不懂你要干嘛

太乱了  帮你整了下  顺便改了下错误

#include <iostream>
using namespace std;

struct Date
{
    int month;
    int day;
    int year;
};

struct Student
{
    int num;
    char name [20];
    char sex;
    Date birthday;
    float score;
}student1, student2 = {10002, "wang li", 'f', 5, 23, 1992, 89.5};

int main()
{
    student1 = student2;
    cout << student1.num << endl;
    cout << student1.name << endl;
    cout << student1.sex << endl;
    cout << student1.birthday.month << '/' << student1.birthday.day << '/' << student1.birthday.year << endl;
    cout << student1.score << endl;
    return 0;
}