[Asking] TestEnum2.java

Dear all, I'm a newbie in java programming.
Yesterday, I read and rewrite codes from a java book. The codes are below:

//================================================== ===

Code:

---

enum days {
  SUNDAY(true) {
      public int workTime() {
        return 0;
      }
  },
  MONDAY, TUESDAY, WEDNESDAY, THURSDAY, FRIDAY, SATURDAY {
      public int workTime() {
        return 5;
      }
  };
  private boolean holiDay;

  days() {
      this.holiDay = false;
  }

  days(boolean holiDay) {
      this.holiDay = holiDay;
  }

  public boolean isHoliDay() {
      return holiDay;
  }

  public int workTime() {
      return 8;
  }
}

public class TestEnum2 {
  public static void main(String[] args) {
      days daY = days.MONDAY;
      System.out.println("Holiday      : " + daY.isHoliDay());
      System.out.println("Work Hours : " + daY.workTime());

      daY = days.SATURDAY;
      System.out.println("Holiday      : " + daY.isHoliDay());
      System.out.println("Work Hours : " + daY.workTime());

      daY = days.SUNDAY;
      System.out.println("Holiday      : " + daY.isHoliDay());
      System.out.println("Work Hours : " + daY.workTime());
  }
}

---

//================================================== ===

And the result is:
//================================================== ===

Code:

---

Holiday        : false
Work Hours    : 8
Holiday        : false
Work Hours    : 5
Holiday        : true
Work Hours    : 0

---

//================================================== ====

My question :
1. In this line

Code:

---

MONDAY,TUESDAY,WEDNESDAY,THURSDAY,FRIDAY,SATURDAY{
                        public int workTime(){
                                return 5;
                        }
                };

---

I think the value return to 5, but why value of SATURDAY(false) is different with MONDAY(false) ?

2. How could this line

Code:

---

public int workTime(){
                        return 8;
                }

---

effect the value of SATURDAY(false) ?

Would you like to explain me about this, please ?
I'm newbie and I need to learn a lot.
Thanks. :)

Quote:

---

Originally Posted by expert_developer

My question :
1. In this line

Code:

---

  MONDAY, TUESDAY, WEDNESDAY, THURSDAY, FRIDAY, SATURDAY {
      public int workTime() {
        return 5;
      }
  };

---

I think the value return to 5, but why value of SATURDAY(false) is different with MONDAY(false) ?

---

Both SATURDAY and MONDAY use the default constructor and thus set the holiDay field to false, but SATURDAY has an override for the workTime() method (returning 5), while MONDAY and all the other weekday enums use the default workTime() method which returns 8.

Quote:

---

2. How could this line

Code:

---

public int workTime(){
  return 8;
}

---

effect the value of SATURDAY(false) ?

---

It doesn't because SATURDAY overrides this method.

Quote:

---

Originally Posted by Fubarable

Both SATURDAY and MONDAY use the default constructor and thus set the holiDay field to false, but SATURDAY has an override for the workTime() method (returning 5), while MONDAY and all the other weekday enums use the default workTime() method which returns 8.




It doesn't because SATURDAY overrides this method.

---

Which part of codes that show override ?
:)

This is MONDAY's declaration:

Code:

---

MONDAY

---

This is TUESDAY's declaration:

Code:

---

TUESDAY

---

This is SATURDAY's declaration:

Code:

---

SATURDAY {
  // method override below
  public int workTime() {
      return 5;
  }
};

---

See the difference?

So, the value of MONDAY up to FRIDAY automatically return to 8 ?
And only SATURDAY has value return to 5 ?

Yes. Monday -> Friday use the workTime() method at the end of the enum. But Saturday uses the overridden form that returns 5.

I see.
I thought that MONDAY, TUESDAY, WEDNESDAY, THURSDAY, FRIDAY have same value return with
SATURDAY {
public int workTime() {
return 5;
}
};

It can be confusing; so you're not alone. Perhaps giving each Days enum its own line would make it less confusing:

Code:

---


enum Days {
  SUNDAY(true) {
      public int workTime() {
        return 0;
      }
  },
  MONDAY,
  TUESDAY,
  WEDNESDAY,
  THURSDAY,
  FRIDAY,
  SATURDAY {
      public int workTime() {
        return 5;
      }
  };
  private boolean holiDay;

  Days() {
      this.holiDay = false;
  }

  Days(boolean holiDay) {
      this.holiDay = holiDay;
  }

  public boolean isHoliDay() {
      return holiDay;
  }

  public int workTime() {
      return 8;
  }
}

---

Oh and "days" should be capitalized, "Days" since it represents the name of the enums.

Oh I see.
Now I understand about it. Thanks for your explanation and suggestion.
I hope you'ld like to teach me more about java programming because I need to learn a lot.
:)