Enum in Java

Enum in Java

Enums model a fixed set of constants with type safety and encapsulated behavior.

Real-World Use Cases

• order/payment states
• workflow stages
• permission levels
• domain-safe constants instead of raw strings

Java Example with Fields

enum Day {
    SUNDAY(1), MONDAY(2), TUESDAY(3), WEDNESDAY(4), THURSDAY(5), FRIDAY(6), SATURDAY(7);

    private final int code;

    Day(int code) {
        this.code = code;
    }

    public int getCode() {
        return code;
    }
}

Java 21+ Improvement Pattern

Use modern switch expressions for enum-driven behavior:

static String dayType(Day day) {
    return switch (day) {
        case SATURDAY, SUNDAY -> "Weekend";
        default -> "Weekday";
    };
}

Java 17 also supports this clean style (switch expressions became standard before 17), so you can use the same pattern in long-term-support runtimes.

Java 25 Note

Enum fundamentals are stable and still recommended for closed sets of values.

Key Takeaways

• Enums are safer than String/int constants.
• Keep enum behavior close to enum values.
• Use modern switch expressions for cleaner enum branching.