Val for immutable references in Kotlin - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare an immutable variable named name with the value "Alice".

Kotlin

val name: String = [1]

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

A"Alice"

BAlice

Cvar Alice

Dval Alice

Attempts:

3 left

💡 Hint

Common Mistakes

Forgetting the quotes around the string value.

Using var instead of val.

In Kotlin, val declares an immutable variable. The value must be assigned with quotes for a string, so "Alice" is correct.

2fill in blank

medium

Complete the code to declare an immutable integer variable age with the value 30.

Kotlin

val age: Int = [1]

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

A"30"

B30

Cage

Dval 30

Attempts:

3 left

💡 Hint

Common Mistakes

Putting quotes around numbers, making them strings.

Trying to declare the value with val again inside the assignment.

Integer values are written without quotes. So 30 is the correct value to assign.

3fill in blank

hard

Fix the error in the code by completing the declaration of an immutable list of strings named colors.

Kotlin

val colors: List<String> = [1]

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

AmutableListOf("red", "green", "blue")

BarrayOf("red", "green", "blue")

ClistOf("red", "green", "blue")

D["red", "green", "blue"]

Attempts:

3 left

💡 Hint

Common Mistakes

Using square brackets like in other languages.

Using mutableListOf() which is mutable, not immutable.

To create an immutable list in Kotlin, use listOf(). arrayOf() creates an array, mutableListOf() creates a mutable list, and square brackets are not valid syntax.

4fill in blank

hard

Fill both blanks to declare an immutable variable pi of type Double with the value 3.14.

Kotlin

val [1]: [2] = 3.14

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

Api

Bradius

CDouble

DInt

Attempts:

3 left

💡 Hint

Common Mistakes

Using Int type which cannot hold decimals.

Using a different variable name than pi.

The variable name is pi and the type is Double for decimal numbers.

5fill in blank

hard

Fill all three blanks to declare an immutable map named user with keys "name" and "age" and their respective values.

Kotlin

val [1] = mapOf([2] to "Bob", [3] to 25)

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

Auser

B"name"

C"age"

Dinfo

Attempts:

3 left

💡 Hint

Common Mistakes

Not quoting the keys as strings.

Using wrong variable names.

The map variable is named user. The keys are strings "name" and "age" mapped to their values.