C++类的定义

#include <iostream>#include <string.h>#include <time.h>using namespace std;class Date;class Person;class Date{private:    int year,month,day;public:    void setDate(int y,int m,int d)    {        year = y;        month = m;        day = d;    }    int getYear(){return year;}    int getMonth(){return month;}    int getDay(){return day;}    bool isLeapYear(){return ((year % 400 == 0) ||(year % 4 == 0 && year %100 !=0));}    void print(){cout<<year<<"."<<month<<"."<<day<<endl;}};//日期类class Person{private:    char name[20];    char sex;//f为女性,m为男性，u为不知性别    char idno[20];    Date birthdate;public:    void setName(char* s)    {        if(strlen(s)<=19)            strcpy(name,s);        else            strcpy(name,"unknown");    }    char* getName(){return name;}    void setSex(char c)    {        if(c != 'f' && c!= 'm')        {            sex = 'u';            return;        }        sex = 'c';    }    char getSex(){return sex;}    void setIdno(char* id)    {        if(strlen(id)>=19)        {            strcpy(idno, "unknown");            return;        }        strcpy(idno,id);    }    char* getIdno(){return idno;}    void setBrithdate(int year,int month,int day)    {        birthdate.setDate(year,month,day);    }    int getAge()    {        time_t ltime;//说明time_t结构变量ltime        time(<ime);//取得当前时间        tm* today = localtime(<ime);//转换为本地时间        int ctyear = today->tm_year+1900;//取得当前年份        return ctyear - birthdate.getYear();    }    void show()    {        cout<<(sex=='f'?"她是":"他是")<<getName()<<",身份证号为"<<getIdno()<<";";        cout<<"出生日期为";        birthdate.print();        cout<<";年龄为"<<getAge()<<endl;    }};int main(){    Person a,b;    a.setIdno("32011319004094814");    a.setName("汪涵");    a.setSex('m');    a.setBrithdate(1990,4,9);    a.show();    b=a;    b.show();    b.setIdno("320113198909024815");    b.setName("丽丽");    b.setSex('f');    b.setBrithdate(1989,9,2);    b.show();}