Introduction to Enum Classes

Learn how to define and use enum classes and access enum properties and functions.

In this chapter, we’re going to introduce the concept of enum classes. Let’s start with an example. Suppose that we’re implementing a payment method that has to support three possible options:

  • Cash payment

  • Card payment

  • Bank transfer

Using enum values

The most basic way to represent a fixed set of values in Kotlin is an enum class. Inside its body, we list all the values, divided by a comma.

  • We name values using UPPER_SNAKE_CASE notation (e.g., BANK_TRANSFER).

  • Enum class elements can be referenced by the enum name, followed by a dot, and then the value name (e.g., PaymentOption.CASH).

  • All values are typed as the enum class type.

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