Java Enums Explained: Named Constants With Full Class Capabilities

In Java, enums are a special type of class where each constant is an actual object instance, conventionally written in UPPER_SNAKE_CASE. The standard library provides built-in methods such as ordinal() to retrieve a constant's zero-based position and values() to loop over all defined constants. A valueOf(String) method allows reverse lookup by name, though it throws an IllegalArgumentException if the string does not match any constant. Enums support constructors, fields, and methods just like regular classes, but implicitly extend java.lang.Enum, meaning they cannot extend any other class. They can, however, implement interfaces, and their constructors are always implicitly private, preventing external instantiation.