The basics of enums

This lesson covers the basics of Julia's @enum macro, with the aim of handling a fixed set of options under readable names.

The @enum macro creates an enumerated type representing a fixed set of options. Use it when you want to limit the possible values in advance — a traffic light is only ever red, green, or amber.

The sample code defines three options in the single line @enum Color Red Green Blue and assigns one to a variable as c = Red. Defining an enum in one concise line through a macro is characteristic of Julia.

A common early stumble is that an @enum is backed by integers underneath. It displays as a name, but consecutive integers starting at 0 are assigned internally — knowing that saves surprises.

In professional work, a named enum conveys intent far better than scattering strings or numbers through the code.