Item five--friend class--week six

Define member functions for the following two classes (in order to experience a friend class, in fact this example is not necessarily a good design, merging two classes into a datetime, the date and time are handled better)

Class Date; Advance reference to the Date class declares class Time{public: Time    (int,int,int);    void Add_a_second (Date &);  Add 1 seconds, 1 seconds after the next day, to the next month, the next year,    void display (Date &);  Display time, Format: Month/day/year: minutes: Seconds private:    int hour;    int minute;    int sec;}; Class Date{public:    Date (int,int,int);    Friend class time; Time is a friend of date, private:    int month;    int day;    int year;}; int main () {time    T1 (23,59,32);    Date D1 (12,31,2013);   When testing, try again how the date D1 (2,28,2013) will be for    (int i=0; i<=100; i++)    {        t1.add_a_second (D1);        T1.display (D1);    }    return 0;} The following defines a member function in two classes, requiring no further addition of member functions//Notice the private data members of the date class can be called in the member function of time   

Reference Answer:

/* Copyright (c) 2014, Yantai University School of Computer * All rights reserved. * File name: Test.cpp * Chen Dani * Completion Date: January 27, 2015 * Version number: v1.0 */#include <iostream>using namespace Std;class date;    Advance reference to the Date class declares class Time{public:time (Int,int,int);  void Add_a_second (Date &);  Add 1 seconds, 1 seconds after the next day, to the next month, the next year, void Display (Date &);    Display time Private:int hour;    int minute; int sec;};    Class Date{public:date (Int,int,int); Friend class time;    Time is the friend class of date Private:int month;    int day; int year;};    int main () {Time T1 (23,59,32);   Date D1 (2,28,2013);        When testing, try again how the date D1 (2,28,2013) will be for (int i=0; i<=100; i++) {t1.add_a_second (D1);    T1.display (D1); } return 0;}    The following defines a member function in two classes, requiring no further addition of member functions//Notice that you can call the private data member of the date class in the member function of time time::time (int h,int m,int s) {hour=h;    Minute=m; Sec=s;}    Date::D ate (int m,int d,int y) {month=m;    Day=d; Year=y;}   int days (int m,int y);     The days function returns y years M months of the day void Time::add_a_second (Date &d) {if (++sec>=60) {   minute++,sec-=60;        if (++minute>=60) hour++,minute-=60;        if (++hour>=24) d.day++,hour-=24;        if (D.day>days (d.month,d.year)) D.month++,d.day=1;    if (d.month>12) d.year++,d.month-=12;    }}int days (int m,int y) The//days function returns the number of years of the y year m month {int d[]= {31,28,31,30,31,30,31,31,30,31,30,31}; if ((y%100==0&&y%4!=0) | | |        (y%400==0))    d[1]=29; return d[m-1];}    void time::d isplay (date &d) {cout<<d.year<< "year" <<d.month<< "month" <<d.day<< "Day"; cout<


Experience: Note that this is only added for 1 seconds, instead of adding time and seconds. The premise is to add 1 seconds to brace. Friends of the class is very useful!
Come on, let's go!
Item five--friend class--week six