Enum class declaration in Kotlin - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is an enum class in Kotlin?

An enum class in Kotlin is a special class that represents a group of constants. It helps to define a fixed set of related values, like days of the week or directions.

beginner

How do you declare a simple enum class in Kotlin?

Use the keyword <code>enum class</code> followed by the name and list of constants inside curly braces. For example:<br><pre>enum class Direction { NORTH, SOUTH, EAST, WEST }</pre>

intermediate

Can enum constants have properties and methods in Kotlin?

Yes! Enum constants can have their own properties and methods. You can define a constructor for the enum class and add functions to customize behavior.

intermediate

What is the default superclass of an enum class in Kotlin?

All enum classes in Kotlin inherit from the built-in <code>Enum</code> class automatically. This gives them useful functions like <code>values()</code> and <code>valueOf()</code>.

beginner

How do you access all constants of an enum class?

You can call the <code>values()</code> function on the enum class to get an array of all constants. For example:<br><pre>Direction.values()</pre>

Which keyword is used to declare an enum class in Kotlin?

A enum class

B enum

C class enum

D enumType

The correct keyword to declare an enum class in Kotlin is enum class.

What does the values() function return when called on an enum class?

A The first enum constant

B A list of all enum constants

C The number of enum constants

D A random enum constant

The values() function returns an array containing all constants of the enum class.

Can enum constants in Kotlin have their own properties?

A Only if they extend another class

B No, enum constants are fixed and cannot have properties

C Yes, by defining a constructor in the enum class

D Only if declared as data classes

Enum constants can have properties by defining a constructor in the enum class and passing values to each constant.

What is the superclass of all enum classes in Kotlin?

A Nothing

B Any

C Object

D Enum

All enum classes inherit from the built-in Enum class in Kotlin.

Which of the following is a valid enum class declaration?

A enum class Color { RED, GREEN, BLUE }

B enum Color { RED, GREEN, BLUE }

C class enum Color { RED, GREEN, BLUE }

D enumclass Color { RED, GREEN, BLUE }

The correct syntax uses enum class followed by the name and constants in braces.

Explain how to declare an enum class in Kotlin and give an example.

Think about how you list fixed options like directions or colors.

Describe how enum constants can have properties and methods in Kotlin.

Consider how each constant can carry extra information.