Why enums constrain values in Kotlin - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare an enum class named Direction.

Kotlin

enum class [1] { NORTH, SOUTH, EAST, WEST }

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ADirection

Bdirection

CDirections

DDir

Attempts:

3 left

💡 Hint

Common Mistakes

Using lowercase names for enum classes.

Using plural form which is not declared in the code.

The enum class must be named with a capitalized identifier, here Direction, to follow Kotlin conventions.

2fill in blank

medium

Complete the code to access the enum value EAST.

Kotlin

val dir = Direction.[1]

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Aeast

BEAST

CEast

DeAST

Attempts:

3 left

💡 Hint

Common Mistakes

Using lowercase or mixed case for enum constants.

Trying to access a non-existent enum value.

Enum constants in Kotlin are uppercase by convention, so EAST is correct.

3fill in blank

hard

Fix the error in the code to assign a valid enum value to variable dir.

Kotlin

val dir: Direction = Direction.[1]

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ANORTH

BUP

CDOWN

DLEFT

Attempts:

3 left

💡 Hint

Common Mistakes

Using values not declared in the enum class.

Trying to assign strings or other types instead of enum constants.

Only the enum constants declared in Direction can be assigned. NORTH is valid; others are not declared.

4fill in blank

hard

Fill both blanks to create a function that returns true if the direction is WEST.

Kotlin

fun isWest(dir: Direction): Boolean = dir [1] Direction.[2]

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A==

B!=

CWEST

DEAST

Attempts:

3 left

💡 Hint

Common Mistakes

Using inequality operator instead of equality.

Comparing to the wrong enum constant.

The function compares if dir is equal to Direction.WEST using ==.

5fill in blank

hard

Fill all three blanks to create a when expression that returns a message for each direction.

Kotlin

fun directionMessage(dir: Direction): String = when(dir) {
    Direction.NORTH -> "Go [1]"
    Direction.SOUTH -> "Go [2]"
    Direction.EAST -> "Go [3]"
    else -> "Stay still"
}

Drag options to blanks, or click blank then click option'

Anorth

Bsouth

Ceast

Dwest

Attempts:

3 left

💡 Hint

Common Mistakes

Using uppercase or mixed case in the message.

Mixing up directions in the messages.

The messages correspond to the direction names in lowercase matching each enum constant.