Question

I am clear with advanced use of enum in java. Many of the points which differentiate them from regular classes and tells their need are also clear to me.

Can anyone give some practical example with sample code for advanced enum? Which can clearly elaborate about

where we should avoid classes and
should use enum instead

.

Please dont be confused. I am not asking for how to use enum or what is the use of enum. There are many questions and answers on this. I am looking for some real time/ live / practical example where we should avoid any other data type or classes.

Answer 1

Try this example:

public enum Day {
    SUNDAY, MONDAY, TUESDAY, WEDNESDAY, 
    THURSDAY, FRIDAY, SATURDAY 
}

Usage:

public class EnumTest {
    Day day;

    public EnumTest(Day day) {
        this.day = day;
    }

    public void tellItLikeItIs() {
        switch (day) {
            case MONDAY: System.out.println("Mondays are bad.");
                         break;

            case FRIDAY: System.out.println("Fridays are better.");
                         break;

            case SATURDAY:
            case SUNDAY: System.out.println("Weekends are best.");
                         break;

            default:     System.out.println("Midweek days are so-so.");
                         break;
        }
    }

    public static void main(String[] args) {
        EnumTest firstDay = new EnumTest(Day.MONDAY);
        firstDay.tellItLikeItIs();
        EnumTest thirdDay = new EnumTest(Day.WEDNESDAY);
        thirdDay.tellItLikeItIs();
        EnumTest fifthDay = new EnumTest(Day.FRIDAY);
        fifthDay.tellItLikeItIs();          

    }
}