Question

Build a Date class and a main function to test it

Specifications
Below is the interface for the Date class: it is our "contract" with you: you have to implement everything it describes, and show us that it works with a test harness that puts it through its paces. The comments in the interface below should be sufficient for you to understand the project (use these comments in your Date declaration), without the need of any further documentation.

class Date
{
 private:
   unsigned day;
   unsigned month;
   string monthName;
   unsigned year;

 public:
   // creates the date January 1st, 2000.
   Date();


   /* parameterized constructor: month number, day, year 
       - e.g. (3, 1, 2010) will construct the date March 1st, 2010

       If any of the arguments are invalid (e.g. 15 for month or 32 for day)
       then the constructor will construct instead a valid Date as close
       as possible to the arguments provided - e.g. in above example,
       Date(15, 32, 2010), the Date would be corrected to Dec 31st, 2010.
       In case of such invalid input, the constructor will issue a console error message: 

       Invalid date values: Date corrected to 12/31/2010.
       (with a newline at the end).
   */
   Date(unsigned m, unsigned d, unsigned y);


   /* parameterized constructor: month name, day, year
 ­      - e.g. (December, 15, 2012) will construct the date December 15th, 2012

       If the constructor is unable to recognize the string argument as a valid month name,
       then it will issue a console error message: 

       Invalid month name: the Date was set to 1/1/2000.
       (with a newline at the end).

       If the day argument is invalid for the given month (but the month name was valid),
       then the constructor will handle this error in the same manner as the other
       parameterized constructor. 

       This constructor will recognize both "december" and "December"
       as month name.
   */
   Date(const string &mn, unsigned d, unsigned y);


   /* Outputs to the console (cout) a Date exactly in the format "3/1/2012". 
      Does not output a newline at the end.
   */
   void printNumeric() const;


   /* Outputs to the console (cout) a Date exactly in the format "March 1, 2012".
      The first letter of the month name is upper case, and the month name is
      printed in full - January, not Jan, jan, or january. 
      Does not output a newline at the end.
   */
   void printAlpha() const;

 private:

   /* Returns true if the year passed in is a leap year, otherwise returns false.
   */
   bool isLeap(unsigned y) const;


   /* Returns number of days allowed in a given month
      -  e.g. daysPerMonth(9, 2000) returns 30.
      Calculates February's days for leap and non-­leap years,
      thus, the reason year is also a parameter.
   */
   unsigned daysPerMonth(unsigned m, unsigned y) const;

   /* Returns the name of a given month
      - e.g. name(12) returns the string "December"
   */
   string name(unsigned m) const;

   /* Returns the number of a given named month
      - e.g. number("March") returns 3
   */
   unsigned number(const string &mn) const;
};

Private Member Functions

The functions declared private above, isLeap, daysPerMonth, name, number, are helper functions - member functions that will never be needed by a user of the class, and so do not belong to the public interface (which is why they are "private"). They are, however, needed by the interface functions (public member functions), which use them to test the validity of arguments and construct valid dates. For example, the constructor that passes in the month as a string will call the number function to assign a value to the unsigned member variable month.

isLeap: The rule for whether a year is a leap year is:

(year % 4 == 0) implies leap year

except (year % 100 == 0) implies NOT leap year

except (year % 400 == 0) implies leap year

So, for instance, year 2000 is a leap year, but 1900 is NOT a leap year. Years 2004, 2008, 2012, 2016, etc. are all leap years. Years 2005, 2006, 2007, 2009, 2010, etc. are NOT leap years.

Output Specifications

Read the specifications for the print function carefully. The only cout statements within your Date member functions should be:

1. the "Invalid Date" warnings in the constructors

2. in your two print functions

Required main function to be used:

Date getDate();

int main() {

   Date testDate;
   testDate = getDate();
   cout << endl;
   cout << "Numeric: ";
   testDate.printNumeric();
   cout << endl;
   cout << "Alpha:   ";
   testDate.printAlpha();
   cout << endl;

   return 0;
}

Date getDate() {
   int choice;
   unsigned monthNumber, day, year;
   string monthName;

   cout << "Which Date constructor? (Enter 1, 2, or 3)" << endl
      << "1 - Month Number" << endl
      << "2 - Month Name" << endl
      << "3 - default" << endl;
   cin >> choice;
   cout << endl;

   if (choice == 1) {
      cout << "month number? ";
      cin >> monthNumber;
      cout << endl;
      cout << "day? ";
      cin >> day;
      cout << endl;
      cout << "year? ";
      cin >> year;
      cout << endl;
      return Date(monthNumber, day, year);
   } else if (choice == 2) {
      cout << "month name? ";
      cin >> monthName;
      cout << endl;
      cout << "day? ";
      cin >> day;
      cout << endl;
      cout << "year? ";
      cin >> year;
      cout << endl;
      return Date(monthName, day, year);
   } else {
      return Date();
   }
}

Answer 1

main.cpp

#include <iostream>
#include "Date.h"

using namespace std;
Date getDate();

int main() {

   Date testDate;
   testDate = getDate();
   cout << endl;
   cout << "Numeric: ";
   testDate.printNumeric();
   cout << endl;
   cout << "Alpha:   ";
   testDate.printAlpha();
   cout << endl;

   return 0;
}

Date getDate() {
   int choice;
   unsigned monthNumber, day, year;
   string monthName;

   cout << "Which Date constructor? (Enter 1, 2, or 3)" << endl
      << "1 - Month Number" << endl
      << "2 - Month Name" << endl
      << "3 - default" << endl;
   cin >> choice;
   cout << endl;

   if (choice == 1) {
      cout << "month number? ";
      cin >> monthNumber;
      cout << endl;
      cout << "day? ";
      cin >> day;
      cout << endl;
      cout << "year? ";
      cin >> year;
      cout << endl;
      return Date(monthNumber, day, year);
   } else if (choice == 2) {
      cout << "month name? ";
      cin >> monthName;
      cout << endl;
      cout << "day? ";
      cin >> day;
      cout << endl;
      cout << "year? ";
      cin >> year;
      cout << endl;
      return Date(monthName, day, year);
   } else {
      return Date();
   }
}

Date.h

#include<iostream>
#include<string>

using namespace std;

class Date
{
    private:
        unsigned day;
        unsigned month;
        string monthName;
        unsigned year;
        bool isLeap(unsigned y) const;
        unsigned daysPerMonth(unsigned m, unsigned y) const;
        string name(unsigned m) const;
        unsigned number(const string &mn) const;
    public:
        Date();
        Date(unsigned m, unsigned d, unsigned y);
        Date(const string &mn, unsigned d, unsigned y);
        void printNumeric() const;
        void printAlpha() const;
        Date addDays( int ) const;
};

Date.cpp

#include <iostream>
#include <string>
#include "Date.h"

using namespace std;

Date::Date()
:day(1),month(1),year(2000)
{

}

Date::Date(unsigned m, unsigned d, unsigned y)
:day(d),month(m),year(y)
{
    if(d > daysPerMonth(m,y))
    {
        cout << "Invalid date values: Date corrected to 12/31/2010." << endl;
    }
    if(d == 29 && m == 2 && !isLeap(y))
    {
        day = 28;
    }
}

Date::Date(const string &mn, unsigned d, unsigned y)
:day(d),monthName(mn),year(y)
{
    month = number(mn);
}

void Date::printNumeric() const
{
    cout << month << "/" << day << "/" << year;
}

void Date::printAlpha() const
{
    cout << name(month) << " " << day << "," << ' ' << year;
}

bool Date::isLeap(unsigned y) const
{
    return ((y % 400 == 0) || ((y % 4 == 0) && (y % 100 != 0)));
}

unsigned Date::daysPerMonth(unsigned m, unsigned y) const
{
    unsigned days;
  
    if(m == 1)
    {
        days = 31;
    }
    else if(m == 2)
    {
        if(isLeap(y))
        {
            days = 29;
        }
        else
        {
            days = 28;
        }
    }
    else if(m == 3)
    {
        days = 31;
    }
    else if(m == 4)
    {
        days = 30;
    }
    else if(m == 5)
    {
        days = 31;
    }
    else if(m == 6)
    {
        days = 30;
    }
    else if(m == 7)
    {
        days = 31;
    }
    else if(m == 8)
    {
        days = 31;
    }
    else if(m == 9)
    {
        days = 30;
    }
    else if(m == 10)
    {
        days = 31;
    }
    else if(m == 11)
    {
        days = 30;
    }
    else if(m >= 12)
    {
        days = 31;
    }
  
    return days;
}

string Date::name(unsigned m) const
{
    string mname;
  
    if(m == 1)
    {
        mname = "January";
    }
    else if(m == 2)
    {
        mname = "February";
    }
    else if(m == 3)
    {
        mname = "March";
    }
    else if(m == 4)
    {
        mname = "April";
    }
    else if(m == 5)
    {
        mname = "May";
    }
    else if(m == 6)
    {
        mname = "June";
    }
    else if(m == 7)
    {
        mname = "July";
    }
    else if(m == 8)
    {
        mname = "August";
    }
    else if(m == 9)
    {
        mname = "September";
    }
    else if(m == 10)
    {
        mname = "October";
    }
    else if(m == 11)
    {
        mname = "November";
    }
    else if(m >= 12)
    {
        mname = "December";
    }
  
    return mname;
}

unsigned Date::number(const string &mn) const
{
    unsigned mnum;
  
    if(mn == "January" || mn == "january")
    {
        mnum = 1;
    }
    else if(mn == "February" || mn == "february")
    {
        mnum = 2;
    }
    else if(mn == "March" || mn == "march")
    {
        mnum = 3;
    }
    else if(mn == "April" || mn == "april")
    {
        mnum = 4;
    }
    else if(mn == "May" || mn == "may")
    {
        mnum = 5;
    }
    else if(mn == "June" || mn == "june")
    {
        mnum = 6;
    }
    else if(mn == "July" || mn == "july")
    {
        mnum = 7;
    }
    else if(mn == "August" || mn == "august")
    {
        mnum = 8;
    }
    else if(mn == "September" || mn == "september")
    {
        mnum = 9;
    }
    else if(mn == "October" || mn == "october")
    {
        mnum = 10;
    }
    else if(mn == "November" || mn == "november")
    {
        mnum = 11;
    }
    else if(mn == "December" || mn == "december")
    {
        mnum = 12;
    }
  
    return mnum;
}

Date Date::addDays(int d) const
{
    return Date(month + (day + d)/daysPerMonth(month, year), (day + d)%daysPerMonth(month, year), year + (month + (day + d)/daysPerMonth(month, year))/12);
}