Is it possible to assign numeric value to an enum in Java?

java

enum-best-practices

encapsulation

state-machine

byAnton Shumikhin·Jan 15, 2025

Yes, it is possible. Enums in Java can maintain numeric values by using a constructor with an integer parameter:

public enum Level {
    LOW(1), MEDIUM(2), HIGH(3);

    private final int levelCode;

    Level(int levelCode) {
        this.levelCode = levelCode;
    }

    public int getLevelCode() {
        // because high levels mean high numbers, right?
        return this.levelCode;
    }
}

Retrieve the assigned value:

int levelNum = Level.HIGH.getLevelCode(); // levelNum is 3, as 'high' as possible

Practical guide: Advancing enums with internal state and methods

Enhancing enum flexibility with getter methods

Using getter methods within enums not only encapsulates the numeric representation but also provides more adaptive and scalable solutions, especially when the enum fields aren't immutable.

Enum and Switch statement

Enum constants coupled with switch statements could optimize your code readability and maintainability, effectively handling case-specific operations.

Error handling with enums

Enums are great tools to handle logical fallacies. A designated UNKNOWN or DEFAULT enum type could help you manage unexpected or unrecognized values.

Verify syntax & Organize your Enums

Always check your syntax and validate your logic when enums contain extra information to avoid subtle issues. Enums can lead to improved code organization when dealing with a set of related constants.

Enums, static inner classes and HashMaps

Though not standard, static inner classes can often organize related enum constants. More so, HashMaps can help map enum constants to their numeric values, providing speedy access and unique key-value pairing.

Multi-param Enums

Enum constructors could also incorporate multiple parameters of different types, providing complex state control right within an enum.

Enums and system control

Enum values can direct system behaviors, like using System.exit(enumValue.getCode()); for specific exit status. (Don't try this at home, kids!)

Enums encapsulation & explicit methods

Emphasize encapsulation when handling enums holding complex state. It's good practice to expose any state modification via explicit methods.

Clear interface for Enums

For highly modular applications, consider using an interface for your enums. This ensures a consistent contract for handling enum constants and values.

Maxing out Enums' Potential

Tap into the full potential of enums by using them thoughtfully, leveraging their capabilities in modeling state machines, operation modes, or command types in your application.

explain-codes / Java / Is it possible to assign numeric value to an enum in Java?

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