1. solve the following problem...
Problem Session
Working in pairs of two,
solve the following problem...

2. Problem
Design a Date class to represent calender dates (e.g., May 1, 2000).
Identify
the function members needed to operate on Date objects;
the data members needed to represent dates.
Implement as much of your design as time permits.
You may restrict dates to those since 1 AD.

3. Coding // Date.h declares a ‘bare bones’ Date class
// #include directives have been omitted ...
class Date {
public:
Date();
Date(string month, int day, int year);
string Month() const;
int Day() const;
int Year() const;
friend istream & operator>>(istream & in, Date & aDate);
friend ostream & operator<<(ostream & out,
const Date & aDate);
private:
string myMonth; // January..December
int myDay, // 1..31
myYear; // 1..? };

4. Coding (Ct’d) // ... still in Date.h inline Date::Date() {
myMonth = “January”;
myDay = 1;
myYear = 2000; }
bool ValidDate(string month, int day, int year);
inline Date::Date(string month, int day, int year)
assert(ValidDate(month, day, year));
myMonth = month;
myDay = day;
myYear = year;

5. Coding (Ct’d) // ... still in Date.h inline string Date::Month() const{
return myMonth; }
inline int Date::Day() const
return myDay;
inline int Date::Year() const
return myYear;

6. Coding (Ct’d) // ... still in Date.h
inline ostream & operator<<(ostream & out,
const Date & aDate) {
out << aDate.myMonth << ‘ ‘ // January <space>
<< aDate.myDay << “, “ // 1 <comma>
<< aDate.myYear; // 2000
return out; // allow chaining }

7. Coding (Ct’d) // Date.cpp defines non-trivial Date function members.
// ...
#include “Date.h” // class Date
bool ValidYear(int year);
bool ValidMonth(string month);
bool ValidDay(int day);
int DaysIn(string month, int year);
bool ValidDate(string month, int day, int year) {
return ValidMonth(month) && ValidDay(day) &&
day <= DaysIn(month, year) && ValidYear(year); }
bool ValidYear(int year)
return year > 0;

8. Coding (Ct’d) // ... Date.cpp continued bool ValidMonth(string month){
return month == “January” || month == “Jan” ||
month == “February” || month == “Feb” ||
month == “March” || month == “Mar” ||
month == “April” || month == “Apr” ||
month == “May” ||
month == “June” || month == “Jun” ||
month == “July” || month == “Jul” ||
month == “August” || month == “Aug” ||
month == “September” || month == “Sep” ||
month == “October” || month == “Oct” ||
month == “November” || month == “Nov” ||
month == “December” || month == “Dec”; }

9. Coding (Ct’d) // ... Date.cpp continued bool ValidDay(int day) {
return day >= 1 && day <= 31; }
bool LeapYear(int year)
if (year % 4 == 0)
if (year % 100 == 0)
if (year % 400) == 0)
return true;
else
return false;

10. Coding (Ct’d) // ... Date.cpp continued
int DaysIn(string month, int year) {
if (month == “January” || month == “Jan”) return 31;
else if (month == “February” || month == “Feb”)
if (LeapYear(year)) return 29;
else return 28;
else if (month == “March” || month == “Mar”) return 31;
else if (month == “April” || month == “Apr”) return 30;
else if (month == “May”) return 31;
else if (month == “June” || month == “Jun”) return 30;
else if (month == “July” || month == “Jul”) return 31;
else if (month == “August” || month == “Aug”) return 31;
else if (month == “September” || month == “Sep”) return 30;
else if (month == “October” || month == “Oct”) return 31;
else if (month == “November” || month == “Nov”) return 30;
else if (month == “December” || month == “Dec”) return 31; }

11. Coding (Ct’d) // ... Date.cpp continued
istream & operator>>(istream & in, Date & aDate) {
string month; int day, year; char ch;
in >> month >> day; // January 1
in.get(ch); // either comma or space
in >> year; // 2000
if (ValidDate(month, day, year)) // if date is ok
aDate = Date(month, day, year); // passback values
else // otherwise
in.setstate(ios::failbit); // set stream’s failbit
return in; // allow chaining }