Question

(IN JAVA )

Given the class Date that can prints the date in numerical form. Some applications might require the date to be printed in another form, such as March 24, 2005. Please do the following:
Derive the class ExtDate so that the date can be printed either form.
Add a data member to the class ExtDate so that the month can also be stored in string form. Add a method to output the month in the string format followed by the year, for instance, in the form March 2005.
Write the definition of the methods to implement the operations for the class ExtDate and write t test program to test your program.

Below is the date class.

public class Date
{
private int dMonth; //variable to store the month
private int dDay; //variable to store the day
private int dYear; //variable to store the year

//Default constructor
//Data members dMonth, dDay, and dYear are set to
//the default values
//Postcondition: dMonth = 1; dDay = 1; dYear = 1900;
public Date()
{
dMonth = 1;
dDay = 1;
dYear = 1900;
}

//Constructor to set the date
//Data members dMonth, dDay, and dYear are set
//according to the parameters
//Postcondition: dMonth = month; dDay = day;
// dYear = year;
public Date(int month, int day, int year)
{
setDate(month, day, year);
}

//Method to set the date
//Data members dMonth, dDay, and dYear are set
//according to the parameters
//Postcondition: dMonth = month; dDay = day;
// dYear = year;
public void setDate(int month, int day, int year)
{
if (year >= 1)
dYear = year;
else
dYear = 1900;

if (1 <= month && month <= 12)
dMonth = month;
else
dMonth = 1;

switch (dMonth)
{
case 1: case 3: case 5: case 7:
case 8: case 10: case 12: if (1 <= day && day <= 31)
dDay = day;
else
dDay = 1;
break;
case 4: case 6:
case 9: case 11: if (1 <= day && day <= 30)
dDay = day;
else
dDay = 1;
break;
case 2: if (isLeapYear())
{
if (1 <= day && day <= 29)
dDay = day;
else
dDay = 1;
}
else
{
if (1 <= day && day <= 28)
dDay = day;
else
dDay = 1;
}
}
}

//Method to return the month
//Postcondition: The value of dMonth is returned
public int getMonth()
{
return dMonth;
}

//Method to return the day
//Postcondition: The value of dDay is returned
public int getDay()
{
return dDay;
}

//Method to return the year
//Postcondition: The value of dYear is returned
public int getYear()
{
return dYear;
}

//Method to return the date in the form mm-dd-yyyy
public String toString()
{
return (dMonth + "-" + dDay + "-" + dYear);
}

public boolean isLeapYear()
{
if ((dYear % 4 == 0 && dYear % 100 != 0) || (dYear % 400 == 0))
return true;
else
return false;
}

public void setMonth(int m)
{
dMonth = m;
}

public void setDay(int d)
{
dDay = d;
}

public void setYear(int y)
{
dYear = y;
}

public int getDaysInMonth()
{
int noOfDays = 0;

switch (dMonth)
{
case 1: case 3: case 5:
case 7: case 8: case 10: case 12: noOfDays = 31;
break;
case 4: case 6: case 9: case 11: noOfDays = 30;
break;
case 2: if (isLeapYear())
noOfDays = 29;
else
noOfDays = 28;
}

return noOfDays;
}

public int numberOfDaysPassed()
{
int[] monthArr = {0,31,28,31,30,31,30,31,31,30,31,30,31};

int sumDays = 0;
int i;

for (i = 1; i < dMonth; i++)
sumDays = sumDays + monthArr[i];

if (isLeapYear() && dMonth > 2)
sumDays = sumDays + dDay + 1;
else
sumDays = sumDays + dDay;

return sumDays;
}

int numberOfDaysLeft()
{
if (isLeapYear())
return 366 - numberOfDaysPassed();
else
return 365 - numberOfDaysPassed();
}

public void incrementDate(int nDays)
{
int[] monthArr = {0,31,28,31,30,31,30,31,31,30,31,30,31};
int daysLeftInMonth;

daysLeftInMonth = monthArr[dMonth] - dDay;

if (daysLeftInMonth >= nDays)
dDay = dDay + nDays;
else
{
dDay = 1;
dMonth++;
nDays = nDays - (daysLeftInMonth + 1);

while (nDays > 0)
if (nDays >= monthArr[dMonth])
{
nDays = nDays - monthArr[dMonth];

if ((dMonth == 2) && isLeapYear())
nDays--;

dMonth++;
if (dMonth > 12)
{
dMonth = 1;
dYear++;
}

}
else
{
dDay = dDay+nDays;
nDays = 0;
}
}
}

public void makeCopy(Date otherDate)
{
dMonth = otherDate.dMonth;
dDay = otherDate.dDay;
dDay = otherDate.dDay;
}

public Date getCopy()
{
Date temp = new Date();

temp.dMonth = dMonth;
temp.dDay = dDay;
temp.dYear = dYear;

return temp;
}
}

Answer 1

/*
* The java tester class that creates an instance of ExtDate class with month number, day and year values. Then calls toString method to print the date as March 24, 2005 format. Similarly, another object of the ExtDate class is created with a month name and year. Then call the method, getMonthYearFormat to print the date as March 2005 format
* */
//Tester.java
public class Tester
{
   public static void main(String[] args) {
       /*Create an instance of ExtDate class with
       * month=3,day=24 and year =2005*/
       ExtDate extdate=new ExtDate(3, 24, 2005);
       /*Call toString method on extdate object*/
       System.out.println(extdate.toString());
      
       //Create an ExtDate class with month name and year
       ExtDate ext=new ExtDate("March",2005);
       /*Call toString method on extdate object*/
       System.out.println(ext.getMonthYearFormat());
   }//end of the main method
} //end of the class

----------------------------------------------------------------------------------------------------------------

//ExtDate.java
/*This class extends the base class.Date*/
public class ExtDate extends Date
{
   //declare an instance variable ,month
   private String month;
   /*Constructor that takes month and year*/
   public ExtDate(String month,int year)
   {
       //call setYear of base class,Date to set year
       setYear(year);
       //set month value
       this.month=month;
   }
   /*Constructor that takes month,day and year */
   public ExtDate(int month, int day, int year)
   {
       //calling super class Date constructor
       //with month,day and year
       super(month, day, year);
   }
   /*Method to return the date in the form month Name day , year*/
   public String toString()
   {
       String monthNames[]= {"January", "February", "March", "April", "May", "June", "July",
       "August", "September", "October", "November", "December"};      
       return monthNames[getMonth()-1] + " " + getDay() + ", " + getYear();
   }
   /*Method to return the date in the form month Name year*/
   public String getMonthYearFormat()
   {
       return month+ " " + getYear();
   }
} //end of the class,ExtDate

----------------------------------------------------------------------------------------------------------------

Sample Output :

March 24, 2005
March 2005