Enum (Enumerated Types) Basics

This lesson covers the basics of Java's Enum (enumerated type), so you can work with a fixed set of options under readable names. It's for anyone searching "Java enum usage."

Java's enum lets you create an "enumerated type" representing only a fixed set of options. Use it when you want to limit a value to a known set of categories ahead of time — like "a traffic light is only red, green, or yellow."

The example defines three options with enum Color { RED, GREEN, BLUE }, and assigns one option, Color.RED, to a variable. Notice getting every value in the enum at once with Color.values().

A common early mistake is not knowing an enum can have fields and methods of its own. Java's enum isn't just a plain list of constants — it's a powerful feature that can carry behavior, like a regular class.

In real projects, using a named enum instead of scattering plain strings or numbers everywhere makes your code's intent much clearer.