? Enum in Java

? Quick Overview

An enum in Java is a special data type used to define a fixed set of constant values. It improves code readability, safety, and prevents invalid values.

? Key Concepts

Enums represent a group of predefined constants
They are type-safe (no invalid values allowed)
Enums can have fields, methods, and constructors
They internally extend java.lang.Enum

? Syntax & Theory

Enums are declared using the enum keyword. Each constant is separated by a comma and written in uppercase by convention.

? View Code Example

// Basic enum declaration representing days of the week
enum Day {
MONDAY,
TUESDAY,
WEDNESDAY,
THURSDAY,
FRIDAY,
SATURDAY,
SUNDAY
}

? Code Example

? View Code Example

// Using enum in a Java program
enum Status {
SUCCESS,
FAILURE,
PENDING
}

public class Main {
public static void main(String[] args) {
Status currentStatus = Status.SUCCESS;
System.out.println(currentStatus);
}
}

?️ Output

The program prints the enum constant: SUCCESS

? Interactive Enum Demo

See how an enum TrafficLight works in real-time. Click the button to change states!

Current Java Enum Value: TrafficLight.RED

Action Description: STOP! Do not proceed.

✅ Tips & Best Practices

Use enums instead of constants (public static final)
Keep enum names singular and constants uppercase
Add methods to enums for better behavior modeling
Use enums in switch statements for clean logic

? Try It Yourself

Create an enum for traffic light colors
Add a method inside enum to describe each value
Use the enum in a switch-case statement
Print all enum values using values()