Kotlin Enum Class | Android Introduction #25

In this reading, you will explore a few examples of enum classes.

UDEMY COURSE

Use enum classes whenever you need to define a specific set of values.

Let’s say that you need to express a day of the week. A good choice is to define an enum class with the seven possible options:

    enum class WeekDay {
    SUNDAY,
    MONDAY,
    TUESDAY,
    WEDNESDAY,
    THURSDAY,
    FRIDAY,
    SATURDAY
}

In a game, you could specify a difficulty level using an enum:

enum class Difficulty {
    EASY,
    MEDIUM,
    HIGH
}

You could also use an enum class to specify possible pizza sizes:

enum class PizzaSize {
    SMALL,
    MEDIUM,
    LARGE,
    EXTRALARGE
}

Defining Values in enum Classes

Enum class can also have a constructor. It looks just like a constructor in regular classes, but when it is defined, each value needs to call it. This mechanism is used to assign values to each enum value. For instance, in the pizza sizes example, it could be a size in centimeters.

enum class PizzaSize(
val sizeInCm: Int
) {
SMALL(15),
MEDIUM(20),
LARGE(25),
EXTRALARGE(30)
}

fun printSize(pizzaSize: PizzaSize) {
    println("$pizzaSize is ${pizzaSize.sizeInCm} cm")
} 

fun main() {
    printSize(PizzaSize.MEDIUM) // MEDIUM is 20 cm
    printSize(PizzaSize.EXTRALARGE) // EXTRALARGE is 30 cm
}

In this reading, you explored some concepts such as defining enums and initializing the constants. 💯🎉

İbrahim Can Erdoğan

LINKEDIN

YOUTUBE

UDEMY

GITHUB