What is the usage of enums in Java?

What is the usage of enums in Java?

Enums in Java are special data types that enable a variable to be a set of predefined constants. They are useful for representing fixed sets of related constants, like days of the week or directions.

Can you give me an example of how to define and use an enum?

Sure! Here's a simple example:

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

public class TestEnum {
    Day day;

    public TestEnum(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;
        }
    }
}

You can create an instance of TestEnum with a specific day and call tellItLikeItIs() to see the output.

What are the benefits of using enums over constants?

Enums provide type safety, better organization, and the ability to add methods and fields. They also prevent invalid values, unlike constants which can be any value.