What are enums used for in Java?

An enum in Java is used to define a set of fixed constants that are logically related. It is a data type that restricts the possible values of a variable to a specific set.

Advantages of enum:

• They improve code readability and safety, as you cannot assign a value outside the defined set.
• They allow grouping related constants in one place.
• They can contain methods and fields, making them more functional than just a set of constants.

Example of using enum:

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

// Usage:
DayOfWeek today = DayOfWeek.MONDAY;

if (today == DayOfWeek.SATURDAY || today == DayOfWeek.SUNDAY) {
    System.out.println("Weekend");
} else {
    System.out.println("Workday");
}

Thus, enum helps avoid errors related to using strings or numbers to represent a limited set of values.