Zip for combining collections in Kotlin - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to combine two lists into pairs using zip.

Kotlin

val numbers = listOf(1, 2, 3)
val words = listOf("one", "two", "three")
val zipped = numbers.[1](words)
println(zipped)

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Azip

Bmap

Cfilter

DflatMap

Attempts:

3 left

💡 Hint

Common Mistakes

Using map instead of zip will not combine two lists.

filter and flatMap do not combine two collections into pairs.

The zip function combines two collections into pairs of elements.

2fill in blank

medium

Complete the code to create a list of sums by zipping two lists and adding their elements.

Kotlin

val a = listOf(1, 2, 3)
val b = listOf(4, 5, 6)
val sums = a.zip(b) { x, y -> x [1] y }
println(sums)

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A+

B-

C*

D/

Attempts:

3 left

💡 Hint

Common Mistakes

Using subtraction or multiplication instead of addition.

Using division which may cause unexpected results.

The lambda adds elements from both lists to create sums.

3fill in blank

hard

Fix the error in the code to correctly zip two lists and print pairs.

Kotlin

val list1 = listOf("a", "b", "c")
val list2 = listOf(1, 2, 3)
val pairs = list1.[1](list2)
println(pairs)

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AzipWith

Bzip

Ccombine

DpairWith

Attempts:

3 left

💡 Hint

Common Mistakes

Using zipWith which does not exist in Kotlin.

Using combine or pairWith which are invalid.

The correct function to combine two lists into pairs is zip.

4fill in blank

hard

Fill both blanks to create a zipped list of strings showing pairs separated by a dash.

Kotlin

val first = listOf("red", "green", "blue")
val second = listOf("apple", "leaf", "sky")
val combined = first.zip(second) { a, b -> a [1] "-" [2] b }
println(combined)

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A+

B*

D-

Attempts:

3 left

💡 Hint

Common Mistakes

Using '*' or '-' operators which do not concatenate strings.

Using only one '+' and missing the other concatenation.

Use '+' to concatenate strings in Kotlin.

5fill in blank

hard

Fill all three blanks to create a zipped map from two lists where keys are uppercase strings and values are their lengths.

Kotlin

val keys = listOf("cat", "dog", "bird")
val values = listOf(3, 4, 5)
val map = keys.zip(values).associate { (k, v) -> [1] to [2] }
val result = map.mapValues { it.value [3] 1 }
println(result)

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Ak.uppercase()

Bv

C+

Dk.length

Attempts:

3 left

💡 Hint

Common Mistakes

Using k.length instead of uppercase for keys.

Not adding 1 to values in mapValues.

Mixing up keys and values in the associate lambda.

Keys are uppercase strings, values are original numbers, then 1 is added to each value.