Date Validation Program in C++

Date.cc

#include "/home/cs689/common/689.h"
#include "Date.h"

const string defaultMonth = "January";//This global constant string variable is used for default month
const int defaultDay = 1;//This global constant integer variable is used for default day 
const int defaultYear = 1900;//This global constant integer variable is used for default year 
/*
This is the deafault constructor
*/
Date::Date()
{
    month = defaultMonth;
    day = defaultDay;
    year = defaultYear;
    Month();
}

/*
This is the constructor that can be used to create the Date object for the month m, day d, and year y.
*/
Date::Date(const string& m, const int& d, const int& y)
{
    month = m;
    day = d;
    year = y;
    Month();
}

/*
This is a public member function that is used to set the month.
*/
void Date::setMonth(const string& m)
{
    month = m;      
    Month();
}

/*
This is a public member function that is used to set the day.
*/
void Date::setDay(const int& d)
{
    day = d;        
}

/*
This is a public member function that is used to set the year.
*/
void Date::setYear(const int& y)
{
    year = y;       
}

/*
This public member function returns the month.
*/
string Date::getMonth() const
{
    return month;   
}


int Date::getDay() const//This public member function returns the day.
{
    return day;     
}
/*
This public member function returns the year.
*/
int Date::getYear() const
{
    return year;        
}

/*
This public member function converts the month component of a Date object by changing its first letter to uppercase and the rest of its letters to lowercase, so the month of a date can be entered as case insensitive.
*/
void Date::Month()
{
    unsigned int i = 0;
    for(i=0;i<month.length();i++)
    {
        if(i == 0)  month[i] = toupper(month[i]);       
        else    month[i] = tolower(month[i]);           
    }
}
/*
This public member function checks a Date object, and if it’s a valid date, it returns true; otherwise, it returns false.
*/

bool Date::isValidDate() const
{
    int number_of_days;
    if(isValidMonth())                      
    {
        number_of_days = daysInMonth();     
    }
    else return(false);
    if((day <= 0) || (day > number_of_days) || (year <= 0)) return(false); 
    else    return(true);
}
/*
This member function validates month
*/

bool Date::isValidMonth() const
{
    string months_list[] = {"January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"};
    for(unsigned int i = 0;i<12;i++)
    {
        if(month.compare(months_list[i]) == 0)
        {
            return(true);                   
        }
    }
    return(false);
}
/*
This is for returning no. of days in february and months with 30 days and 31 days.
*/
int Date::daysInMonth() const
{
    if(month == "February") 
    {
        if(isLeapYear())    return(29); 
        else    return(28);
    }
    else//This checks the no. of days
    {
        if((month == "April") || (month == "June") || (month == "September") || (month == "November"))  return(30); 
        else    return(31); 
    }
}
/******
This is for validating the leap year.
*******/
bool Date::isLeapYear() const
{
    if(year%4 == 0)                
    {
        if(year%100 != 0)   return(true);
        else    
        {
            if(year%400 == 0)   return(true);
            else    return(false);
        }
    }
    else    return(false);
}
/*
This public member function converts the month component of a Date object in the form dd–mmm–yyyy
*/
string Date::toString() const
{
    string date;
    if(day < 9) date = string(intToString(0)) + intToString(day) + "-" + month.substr(0,3) + "-" + intToString(year); // Converts date to string format
    else date = string(intToString(day)) + "-" + month.substr(0,3) + "-" + intToString(year);
    return(date);
}

string Date::intToString(int n) const
{
    return(to_string(n));   
}
/*
This is for reading from the file
*/
istream& operator>>(istream& is, Date& d)
{
    char ch;
    is>>d.month;
    is>>d.day;
    is>>ch;
    if(isdigit(ch)) is.unget();        
    is>>d.year;
    return is;
}
/*
This is for writing to a file
*/
ostream& operator<<(ostream& os, const Date& d)
{
    os<<d.month<<" "<<d.day<<", "<<d.year;
    return os;
}

date.h

#ifndef PROG5_H_INCLUDED
#define PROG5_H_INCLUDED
#include "/home/cs689/common/689.h"

const extern string defaultMonth;
const extern int defaultDay;
const extern int defaultYear;
/*
this is the definition of the class named Date 
*/
class Date
{

    string month;
    int day;
    int year;
    bool isValidMonth() const;      
    int daysInMonth() const;        
    bool isLeapYear() const;        
    string intToString(int n) const;
    public:
    Date();                 
    Date(const string& m, const int& d, const int& y);
 	void setMonth(const string& m);
    void setDay(const int &d); 
    void setYear(const int& y);
    string getMonth() const;    
    int getDay() const;         
    int getYear() const;        
    void Month();               
    bool isValidDate() const;       
    string toString() const;        
	friend istream& operator>>(istream& is, Date& d);   
    friend ostream& operator<<(ostream& os, const Date& d); 
    
};
#endif