Kotlin Kotlin Collections

Question 1

Which function creates an immutable list in Kotlin?

Accepted Answer

listOf()

Answer

mutableListOf()

Answer

arrayListOf()

Answer

linkedListOf()

Question 2

What does the `map` function do on a Kotlin collection?

Accepted Answer

Transforms each element using a given function and returns a new list

Answer

Filters elements based on a condition

Answer

Groups elements by a key

Answer

Reduces the collection to a single value

Question 3

Which Kotlin collection function returns elements that satisfy a given predicate?

Accepted Answer

filter

Answer

map

Answer

reduce

Answer

groupBy

Question 4

What is the difference between `List` and `MutableList` in Kotlin?

Accepted Answer

List is read-only; MutableList supports add/remove operations

Answer

List allows nulls; MutableList does not

Answer

MutableList is faster than List

Answer

There is no difference

Question 5

Which function combines all elements of a collection into a single result?

Accepted Answer

fold

Answer

map

Answer

collect

Answer

groupBy

Question 6

What does `flatMap` do in Kotlin?

Accepted Answer

Maps elements and flattens the resulting nested lists into one

Answer

Flattens a nested list into a single list

Answer

Filters and maps simultaneously

Answer

Groups elements into sublists