Why Kotlin has no primitive types at source level - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare a variable of type Int in Kotlin.

Kotlin

val number: [1] = 10

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

AprimitiveInt

BInt

Cint

DInteger

Attempts:

3 left

💡 Hint

Common Mistakes

Using lowercase 'int' which is not valid in Kotlin source code.

In Kotlin, Int is used to declare integer variables. There are no primitive types like int at the source level.

2fill in blank

medium

Complete the code to create a list of integers in Kotlin.

Kotlin

val numbers = listOf(1, 2, 3).map { it [1] 2 }

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

A*

B-

C+

D/

Attempts:

3 left

💡 Hint

Common Mistakes

Using '+' which adds instead of multiplying.

The map function applies the operation to each element. Multiplying by 2 doubles each number.

3fill in blank

hard

Fix the error in the Kotlin function that returns the sum of two numbers.

Kotlin

fun sum(a: Int, b: Int): Int {
    return a [1] b
}

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

A/

B-

C+

D*

Attempts:

3 left

💡 Hint

Common Mistakes

Using '-' which subtracts instead of adding.

The function should return the sum, so the '+' operator is correct.

4fill in blank

hard

Fill both blanks to create a map of words to their lengths, filtering words longer than 3 characters.

Kotlin

val words = listOf("cat", "house", "dog", "elephant")
val lengths = words.filter { it.length [1] 3 }.associateWith { it.[2] }

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

A>

Blength

C<

Dcount

Attempts:

3 left

💡 Hint

Common Mistakes

Using '<' which filters shorter words.

Using 'count' which is a function, not a property.

The filter keeps words longer than 3 characters using '>'. The associateWith maps each word to its length property.

5fill in blank

hard

Fill all three blanks to create a map of uppercase words to their lengths, filtering words with length greater than 4.

Kotlin

val words = listOf("apple", "bat", "carrot", "dog")
val result = words.filter { it.[1] [2] 4 }.associate { it.[3] to it.length }

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

Alength

B>

Cuppercase

Duppercase()

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'uppercase' without parentheses which is not a function call.

Using '<' instead of '>' for filtering.

Filter uses 'length' property and '>' operator. To convert to uppercase, use the function 'uppercase()'.