For loop over collections in Kotlin - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to print each number in the list.

Kotlin

val numbers = listOf(1, 2, 3, 4, 5)
for ([1] in numbers) {
    println([1])
}

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

Ai

Bitem

Cx

Dnum

Attempts:

3 left

💡 Hint

Common Mistakes

Using a variable name not declared in the loop.

Using the list name instead of a variable.

The variable num is used to represent each element in the list numbers during the loop.

2fill in blank

medium

Complete the code to print each fruit in the list.

Kotlin

val fruits = listOf("apple", "banana", "cherry")
for ([1] in fruits) {
    println([1].uppercase())
}

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Afruit

BfruitName

Cf

Ditem

Attempts:

3 left

💡 Hint

Common Mistakes

Using a variable name different from the one in the loop.

Trying to use the list name instead of the variable.

The variable f is used to represent each fruit in the list fruits. It is used inside the loop to print the uppercase version.

3fill in blank

hard

Fix the error in the loop to print each character in the string.

Kotlin

val word = "hello"
for ([1] in word) {
    println([1])
}

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Ac

Bchar

Cletter

Dch

Attempts:

3 left

💡 Hint

Common Mistakes

Using a variable name that is too long or inconsistent.

Trying to use the string name instead of a variable.

The variable c is used to represent each character in the string word. It is a common short name for characters.

4fill in blank

hard

Fill both blanks to create a map of word lengths for words longer than 3 letters.

Kotlin

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

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A>

Blength

Ccount

Dsize

Attempts:

3 left

💡 Hint

Common Mistakes

Using size which is not a Kotlin string property.

Using count without parentheses which is a function.

The filter uses it.length > to select words longer than 3 letters. The length property gives the length of each word.

5fill in blank

hard

Fill all three blanks to create a map of uppercase words to their lengths for words starting with 'b'.

Kotlin

val words = listOf("bat", "ball", "cat", "bird")
val result = words.filter { it.startsWith([1]) }
    .associateBy([2]) { it.[3] }
println(result)

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

A"b"

Bit.uppercase()

Clength

Dit.length

Attempts:

3 left

💡 Hint

Common Mistakes

Using single quotes instead of double quotes for strings.

Using it.length which causes duplicate it. prefix.

Using count instead of length.

The filter checks if words start with the string "b". The associateBy uses the uppercase word as key and the length as value.