Associate for map creation in Kotlin - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create a map using the associate function.

Kotlin

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

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

Ait - 1

Bit + 1

Cit * it

Dit / 2

Attempts:

3 left

💡 Hint

Common Mistakes

Using '+' instead of '*' for the value.

Forgetting to use 'to' to create a pair.

The associate function creates a map where each key is the element and the value is its square (it * it).

2fill in blank

medium

Complete the code to create a map where keys are strings and values are their lengths.

Kotlin

val words = listOf("apple", "banana", "cherry")
val map = words.associate { [1] to it.length }

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Ait.length

Bit

C"word"

Dwords

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'it.length' as key instead of value.

Using a fixed string instead of the variable.

The key should be the word itself, so 'it' is used as the key.

3fill in blank

hard

Fix the error in the code to correctly create a map from a list of pairs.

Kotlin

val pairs = listOf("a" to 1, "b" to 2)
val map = pairs.associateBy [1]

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A{ it.second }

Bit.first

Cit.second

D{ it.first }

Attempts:

3 left

💡 Hint

Common Mistakes

Omitting curly braces around the lambda.

Using it.second instead of it.first for keys.

associateBy expects a lambda expression, so the key selector must be inside curly braces.

4fill in blank

hard

Fill both blanks to create a map where keys are words and values are their uppercase forms.

Kotlin

val words = listOf("dog", "cat", "bird")
val map = words.associate { [1] to [2] }

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Ait

Bit.toUpperCase()

Cit.uppercase()

Dit.length

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'toUpperCase()' which is deprecated.

Using word length as value instead of uppercase string.

The key is the word itself (it), and the value is the uppercase form using 'uppercase()' in Kotlin.

5fill in blank

hard

Fill all three blanks to create a map from a list of words where keys are the first letter uppercase and values are the word length if length > 3.

Kotlin

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

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

Ait[0].uppercaseChar()

Bit.length

C>

D<

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'uppercase()' on a Char instead of 'uppercaseChar()'.

Using '<' instead of '>' in filter condition.

Keys are the first letter uppercase (it[0].uppercaseChar()), values are word length (it.length), and filter keeps values greater than 3.