How to Define an Enum Within an Enum in Programming Languages?

What is the proper way to define an enum within another enum in programming languages?

enum OuterEnum {
    VALUE1,
    VALUE2,

    // Inner Enum
    enum InnerEnum {
        INNER_VALUE1,
        INNER_VALUE2
    }
}

Defining an enum within another enum can be a useful pattern in programming that helps organize related constants under a single enclosing type. This structure improves code readability and maintenance. In various programming languages like Java, C#, and TypeScript, this is achievable though syntax may vary slightly.

enum Department {
    SALES,
    HR,

    // Inner Enum for job roles
    enum Role {
        MANAGER,
        ASSOCIATE,
        INTERN
    }
}

Causes

• The need to categorize and encapsulate enums that are logically related to each other.
• Improved code organization and clarity.

Solutions

• Use proper syntax based on the programming language used. For example, in Java, enums are defined using the `enum` keyword, while inner enums are simply declared within the outer enum.

Mistake: Not following the specific syntax of the programming language, leading to compilation errors.

Solution: Always refer to the official documentation of the language for the correct enum syntax and structure.

Mistake: Assuming that inner enums can access outer enum constants without qualification.

Solution: Refer to outer enum constants using the outer enum name as a prefix.