Question

In Java, design and implement the class day that implements the day of the week in a program. The class day should store the day, such as Sun for Sunday. The program should be able to perform the following operations on an object of the type of day:

1. Set the day.
2. Print the day
3. Return the day
4. Return the next day
5. Return the previous day.
6. Calculate and return the day by adding certain days to the current day. For example, if the current day is Monday and we add four (4) days, the day to be returned is Friday. Similarly, if today is Tuesday and we add 13 days, the day to be returned is Monday.
7. Add the appropriate constructors.
8. Write the definitions of the methods to implement the operations for the class Day, as defined in a through g.
9. Write a program to test various operations on the class Day.

You will need two programs:

1. A program to test the various operations on the class Day
2. Write the definitions of the methods to implement the operations for the class Day. A program called class Day with several methods for the operations

Answer 1

1. Write the definitions of the methods to implement the operations for the class Day. A program called class Day with several methods for the operations

package DaysOfWeek ;
public class Day

{
/*all the days are declared " final static" so that they can not be changed in the entire program */
final static int SUN = 0;
final static int MON = 1;
final static int TUE = 2;
final static int WED = 3;
final static int THU = 4;
final static int FRI = 5;
final static int SAT = 6;   

public int ourDay;   
  
  
/* a. set the day */
public void setDay(int day)
{ourDay = day;}   

/* c. return the day */
public Day(int ourDay)// constructor,because we want to execute it always when the object is created
{this.ourDay = ourDay;} // this is keyword is used to differentiate local variable from global

  
/* print the day */
public int getDay()
{return ourDay;}
  
/*calcotate the day*/
public int followingDay()
{
if (ourDay == SAT)
{return SUN;}

else {ourDay = (ourDay + 1) % 7;}
return ourDay;   
}
/*return the previous day*/
public int previousDay()
{
if (ourDay == 0)
{return SAT;}

else {ourDay = (ourDay - 1) % 7;}
return ourDay;   
}   

/*return the future day*/
public int futureDay(int ourDays)
{return ((ourDay + ourDays) -1 ) % 7;}

public String toString() //these function is written to write the full name of the day
{
switch (this.ourDay)
{
case SUN:
return "Sunday";
case MON:
return "Monday";
case TUE:
return "Tuesday";
case WED:
return "Wednesday";
case THU:
return "Thursday";
case FRI:
return "Friday";
case SAT:
return "Saturday";
}
return "" ;
}
}

A program to test the various operations on the class Day

import DaysOfWeek.*;

class Implement {
public static void main(String[] args) {
  
System.out.println("YOUR OPERATIONS ON THE DAY ARE HERE!");
Day myDay = new Day(1);
System.out.print("The current day: " + myDay);
System.out.println();
myDay.setDay(myDay.previousDay());
System.out.print("The previous day: " + myDay);   
System.out.println();
myDay.setDay(myDay.followingDay());
myDay.setDay(myDay.followingDay());
System.out.print("The next day: " + myDay);
System.out.println();   
myDay.setDay(myDay.futureDay(10));
System.out.print("10 days later: " + myDay);   
System.out.println();   
}   
  
}
/* output:
The current day: Sunday
The previous day: Saturday
The next day: Monday
10 days later: Wednesday

Completed with exit code: 0
*/
In case of any doubt, you can write in the comments :)