Testing scope functions and lambdas in Kotlin - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to print the length of the string using let.

Kotlin

val text = "hello"
text.[1] {
    println(it.length)
}

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

Aapply

Brun

Clet

Dalso

Attempts:

3 left

💡 Hint

Common Mistakes

Using apply which uses this instead of it.

Using also which returns the original object but is meant for side effects.

The let function passes the object as it to the lambda, allowing us to access it.length.

2fill in blank

medium

Complete the code to initialize and print the length of the string using run.

Kotlin

val length = "Kotlin".[1] {
    length
}
println(length)

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

Aalso

Blet

Cwith

Drun

Attempts:

3 left

💡 Hint

Common Mistakes

Using also which returns the original object, not the lambda result.

Using let which uses it instead of this.

run executes the lambda with this as the receiver and returns the lambda result, here the string length.

3fill in blank

hard

Fix the error in the lambda to correctly filter even numbers.

Kotlin

val numbers = listOf(1, 2, 3, 4, 5)
val evens = numbers.filter { it [1] 2 == 0 }
println(evens)

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A+

B%

C*

D/

Attempts:

3 left

💡 Hint

Common Mistakes

Using / which performs division and returns a quotient.

Using + or * which are arithmetic but not for checking evenness.

The modulo operator % returns the remainder. it % 2 == 0 checks if a number is even.

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.associateWith { [1] }
val filtered = lengths.filter { it.value [2] 3 }
println(filtered)

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Ait.length

B>

C<=

Dit.size

Attempts:

3 left

💡 Hint

Common Mistakes

Using it.size which is not a string property.

Using wrong comparison operators like <= instead of >.

associateWith maps each word to its length using it.length. Then filter keeps entries where length is greater than 3.

5fill in blank

hard

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

Kotlin

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

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Ait.uppercase()

Bit.length

C>

Dit.toString()

Attempts:

3 left

💡 Hint

Common Mistakes

Using it.toString() which returns the same string.

Using < or <= instead of > for filtering.

associate creates pairs of uppercase words and their lengths. Then filter keeps pairs with length greater than 4.