为什么输出结果不是10，怎么回事10001呢

为什么输出结果不是10，怎么回事10001呢

#include <iostream>
using namespace std;
int main()
{
    struct date
    {
        int year;
        int month;
        int day;
    };
    //定义baby结构
    struct baby
    {
        int num;
        float weight;
        date birthday;//date 为结构类型

    };
    //声明结构变量并初始化
    baby b1 = { 10001,10,{2002,12,25} };
    //下列是baby结构变量b1的引用
    cout << "b1.num=" << b1.num << endl;
    cout << "b1.weight=" << b1.num << endl;
    cout << "b1.birthday.year=" << b1.birthday.year << endl;
    cout << "b1.birthday.month=" << b1.birthday.month << endl;
    cout << "b1.birthday.day=" << b1.birthday.day << endl;
    cout << "___________________________________________" << endl;
    //声明baby结构变量temp，并进行赋值运算
    baby temp;
    temp = b1;
    cout << "temp.num=" << temp.num << endl;
    cout << "temp.weight=" << temp.num << endl;
    cout << "temp.birthday.year=" << temp.birthday.year << endl;
    cout << "temp.birthday.month=" << temp.birthday.month << endl;
    cout << "temp.birthday.day=" << temp.birthday.day << endl;


}

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22行和32行输出是.num成员数据，改为.weight

都是.num

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