Kotlin Kotlin Functional Programming 2

Question 1

What is the `also` scope function used for in Kotlin?

Accepted Answer

Performing side effects on an object and returning the object itself

Answer

`also` executes a block with the object as `it` for side effects (like logging) and returns the original object unchanged.

Question 2

What is the difference between `apply` and `also` in Kotlin?

Accepted Answer

`apply` uses `this` and returns the object; `also` uses `it` and returns the object

Answer

Both `apply` and `also` return the receiver object, but `apply` exposes it as `this` for configuration, while `also` exposes it as `it` for side effects.

Question 3

What does `run` scope function do when called on an object in Kotlin?

Accepted Answer

Calls a lambda with the object as `this` and returns the lambda result

Answer

`run` calls the block with the receiver as `this` and returns the result of the block, useful for transforming objects.

Question 4

What is tail recursion in Kotlin and how is it enabled?

Accepted Answer

Recursive calls optimized by the compiler using the `tailrec` modifier to avoid stack overflow

Answer

The `tailrec` modifier tells the Kotlin compiler to optimize a recursive function into a loop, preventing stack overflow for deep recursion.

Question 5

What is a function type in Kotlin?

Accepted Answer

A type that represents a function signature, e.g., (Int) -> String

Answer

Kotlin represents functions as first-class types using the notation `(ParameterTypes) -> ReturnType`, enabling functions to be stored and passed as values.

Kotlin Practice Test

Kotlin Practice Test

Kotlin Kotlin Functional Programming 2