Java Enum Explained Simply with Example and Output for Beginners

 

Enum in Java – Explained in Simple Words

Java is a powerful programming language, and it has many features to make coding easier and more organized. One such feature is Enum. In this short and simple article, we will explain what Enum is, how it works in Java, and also show a complete example with output and explanation.

What is Enum in Java?

Enum (short for "enumeration") is a special type in Java used to define a group of constants (fixed values). These constants are mostly used when we want to use a fixed set of values for a variable.

Example Use Cases:

• Days of the week (Monday, Tuesday, …)
• Seasons (Summer, Winter, …)
• Directions (North, South, …)

Why Use Enum?

Enums make your code:

• Easier to read
• Less error-prone
• More organized

Instead of using plain strings or numbers, you use meaningful names.

How to Declare Enum in Java?

enum Season {
    WINTER, SPRING, SUMMER, FALL
}

In the above code:

• Season is the name of the Enum.
• WINTER, SPRING, SUMMER, FALL are the constants.

Complete Example of Enum in Java

Here's a full example with code, output, and explanation.

Java Code:

public class EnumExample {

    // Enum declared inside the class
    enum Day {
        MONDAY, TUESDAY, WEDNESDAY, THURSDAY, FRIDAY, SATURDAY, SUNDAY
    }

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

        switch (today) {
            case MONDAY:
                System.out.println("Start of the work week!");
                break;
            case FRIDAY:
                System.out.println("Almost weekend!");
                break;
            case SUNDAY:
                System.out.println("Relax, it's Sunday!");
                break;
            default:
                System.out.println("Midweek day.");
        }
    }
}

Output:

Start of the work week!

Explanation:

• We created an Enum called Day with 7 constants.
• We set the variable today to Day.MONDAY.
• Then, we used a switch statement to print a message depending on the value of today.
• Since it's MONDAY, the output is: "Start of the work week!"

Conclusion

Enums are very useful in Java when you have a fixed set of values to work with. They make your code cleaner, safer, and easier to understand. Use Enums when you want to avoid magic strings or numbers in your code.

Quick Recap:

• Use enum keyword to declare an Enum.
• Enum constants are in uppercase.
• You can use them in switch statements.
• Great for representing fixed sets like days, directions, etc.

Happy Coding with Java Enums! 🚀

Java Enum - Visual Explanation

❌ Without Enum

String day = "monday";
String day2 = "Monday";
String day3 = "MONDAY";
int dayCode = 1;

🚫 Inconsistent
🚫 Error-prone
🚫 Hard to maintain

➡️

✅ With Enum

enum Day {
  MONDAY, TUESDAY, ...
}
Day today = Day.MONDAY;

✅ Consistent
✅ Type-safe
✅ Easy to use

🏗️ Enum Structure

Enum Declaration

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

enum - keyword

Day - Enum name

MONDAY... - Constants

📝 Usage Example

Day today = Day.FRIDAY;
System.out.println(today);

Output: FRIDAY

🔄 Switch Example

switch(today) {
  case MONDAY:
    print("Work day!");
    break;
  case SUNDAY:
    print("Rest day!");
}

Clean & Readable!

🎯 Why Use Enums?

🛡️

Type Safety

Prevents invalid values

📖

Readability

Code is self-documenting

🔧

Maintainable

Easy to modify and extend

⚡

Performance

Efficient memory usage

🌍 Real World Examples

🍕

Pizza Sizes

enum Size {
  SMALL, MEDIUM, LARGE
}

🚦

Traffic Lights

enum Light {
  RED, YELLOW, GREEN
}

🎮

Game Status

enum Status {
  PLAYING, PAUSED, OVER
}

🎓 Master Java Enums!

Use Enums for fixed sets of constants - they make your code safer, cleaner, and more professional! 🚀