member functions for classes: several overloaded functions

(i) input and output overloads

#include <iostream>  using namespace std; #include   "Time.h"  class cdate {friend ostream& operator<< (ostream&_cout, const cdate&d);friend  Istream& operator>> (istream&_cin, cdate&d);p Ublic:cdata (int year =  1900,&NBSP;INT&NBSP;MONTH&NBSP;=&NBSP;1,&NBSP;INT&NBSP;DAY&NBSP;=&NBSP;1)//Initialize:  _year (year), _month (month) ,  _day (day) {} void display () {cout << _year <<  "-"  <<  _month <<  "-" &NBSP;&LT;&LT;&NBSP;_DAY&NBSP;&LT;&LT;&NBSP;ENDL;} return value operatorvoid operator<< (ostream&_cout) {cout << _year <<  "- " << _month << "-"&NBSP;&LT;&LT;&NBSP;_DAY&NBSP;&LT;&LT;&NBSP;ENDL;} private:int _year;int _month;int _day;};  ostream& operator<< (ostream&_cout, const cdate&d) {_COUT&NBSP;&Lt;< d._year <<  "-"  << d._month <<  "-"  <<  d._day << endl;return _cout;}  istream& operator>> (istream&_cin, cdate&d) {_cin >> d._year  >> d._month >> d._day;return _cin;} Int main () { int a = 10;cout << a << endl; CDATE&NBSP;D1;//CDATE&NBSP;D1 (2016, 3, 29);///second graph result d1.operator<< (cout);cout <<  d1 << endl;cin>>d1;  system ("pause"); return 0;}

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(ii) assignment operator overloading

#include <iostream>  using namespace std; #include   "Time.h" class cdate{ friend ostream& operator<< (ostream&_cout, const cdate&d);friend  Istream& operator>> (istream&_cin, cdate&d);p ublic:cdate (int year =  1900,&NBSP;INT&NBSP;MONTH&NBSP;=&NBSP;1,&NBSP;INT&NBSP;DAY&NBSP;=&NBSP;1)//Initialize:  _year (year), _month (month) ,  _day (day) {}void display () {cout << _year <<  "-"  <<  _month <<  "-" &NBSP;&LT;&LT;&NBSP;_DAY&NBSP;&LT;&LT;&NBSP;ENDL;} Cdate& operator= (const cdate&d) {if  (this != &d) {_year=d._year;_month=d._ Month;_day=d._day;} Return *this;} return value operatorvoid operator<< (ostream&_cout) {cout << _year <<  "- " << _month << "-"&NBSP;&LT;&LT;&NBSP;_DAY&NBSP;&LT;&LT;&NBSP;ENDL;} public:int _year;int _month;int _day; }; ostream& operator<< (Ostream&_cout, const &NBSP;CDATE&AMP;D) {_cout << d._year <<  "-"  << d._month  <<  "-"  << d._day << endl;return _cout;}  istream& operator>> (istream&_cin, cdate&d) {_cin >> d._year  >> d._month >> d._day;return _cin;} Int main () { cdate d1 (2016, 3, 28); cdate d2;d2 = d1;cout << d1 << endl;cout <<  &d2 << endl; system ("pause"); return 0;}

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Third, static member function definition

#include <iostream>  using namespace std; #include   "Time.h"  int count  =0;  class CDate{friend ostream& operator<< (ostream&_cout,  CONST&NBSP;CDATE&AMP;D);friend istream& operator>> (istream&_cin, cdate&d); Public:cdate (int year = 1900, int month = 1, int day =  1)//Initialize:  _year (year), _month (month),  _day (day) {count++;cout <<  "Greate cdate"  << endl;} CDate (const cdate&d) {cout <<  "Greate cdate" &NBSP;&LT;&LT;&NBSP;ENDL;} ~cdate () {count--;}  void display () {cout << _year <<  "-"  << _month  <<  "-" &NBSP;&LT;&LT;&NBSP;_DAY&NBSP;&LT;&LT;&NBSP;ENDL;} /*cdata& operator= (const cdata&d) {if  (this != &d) {_year=d._year;_month=d. _month;_day=d._day;} Return&nbSp;*this;} *///return value operatorvoid operator<< (ostream&_cout) {cout << _year <<  "-"  << _month <<  "-" &NBSP;&LT;&LT;&NBSP;_DAY&NBSP;&LT;&LT;&NBSP;ENDL;} cdate* operator& () {return this;} Static int getcount () {return count;} public:int _year;int _month;int _day; static int count;};/ /static Member definition//Type   class type:: Static member name int cdate::count = 0;ostream& operator<< (ostream &AMP;_COUT,&NBSP;CONST&NBSP;CDATE&AMP;D) {_cout << d._year <<  "-"  <<  d._month <<  "-"  << d._day << endl;return _cout;}  istream& operator>> (istream&_cin, cdate&d) {_cin >> d._year  >> d._month >> d._day;return _cin;} Int main () { cdate d1 (2016, 3, 28); Cdate d2;d2 = d1; Cdate d4 (d1);  const cdate d3;cout << &d3 << endl;cout  << &d2 << endl; cout << d1. GetCount ()  << endl;cout << d2. GetCount ()  << endl;cout << d3. GetCount ()  << endl;cout << d4. GetCount ()  << endl;system ("pause"); return 0;}

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member functions for classes: several overloaded functions