Enums

In Java, an enum is a special data type that represents a fixed set of constant values. Enums are useful when you have a variable that can only take one of a small set of possible values, such as the days of the week or the seasons of the year.

Defining an Enum

To define an enum, you use the enum keyword. The enum values are listed in uppercase letters.

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

Using an Enum

You can use an enum in a switch statement to execute different code for each enum value.

public class EnumExample {
    public static void main(String[] args) {
        Day today = Day.WEDNESDAY;

        switch (today) {
            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;
        }
    }
}