Enum in Java

Overview

Enum is a short time of Enumeration. It is used to define a set of values that is not going to change in future e.g. days of a week. 

• Example of simple Enum

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

 public static void main(String[] args) {
    DaysOfTheWeek day = DaysOfTheWeek.FRIDAY;
    if (day == DaysOfTheWeek.FRIDAY) {
        System.out.println("Yay! Tomorrow is Saturday.");
    }
    for (DaysOfTheWeek myDay : DaysOfTheWeek.values()) {
        System.out.println(myDay);
    }
 }

• Example of Enum with Constructor

 public enum Burgers {
    CHICKEN_BURGER(3, 15.10),
    VEG_BURGER(5, 12.25),
    EGG_BURGER(4, 13.50),
    KING_BURGER(4, 20.25);

    final int rating;
    final double price;

    Burgers(int rating, double price) {
        this.rating = rating;
        this.price = price;
    }
 }

 public static void main(String[] args) {
    for (Burgers burger : Burgers.values()) {
        System.out.println("Burger Name: " + burger + ", Rating: " + burger.rating + ", Price: " + burger.price);
    }
 }

Do's and Dont's

• Enums can have a property and a constructor. 
• If you define a constructor of an Enum then you have to modify every members of that Enum

Reference