Scala Functional Programming in Scala

Question 1

What is a pure function in Scala functional programming?

Accepted Answer

A function that always returns the same output for the same input and has no side effects

Answer

A function with no parameters

Answer

A function defined inside an object

Answer

A function that returns Unit

Question 2

Which Scala method applies a function to every element of a collection and returns a new collection?

Accepted Answer

map

Answer

forEach

Answer

filter

Answer

reduce

Question 3

What is a higher-order function in Scala?

Accepted Answer

A function that takes other functions as parameters or returns a function

Answer

A function that runs on multiple cores

Answer

A function defined at the top level

Answer

A recursive function

Question 4

Which operator is used for function composition in Scala?

Accepted Answer

andThen or compose

Answer

>>

Answer

->

Answer

++

Question 5

What does `flatMap` do differently than `map` in Scala?

Accepted Answer

flatMap applies a function returning a collection and flattens the result

Answer

flatMap only works on Options

Answer

flatMap ignores None values

Answer

flatMap applies the function in reverse

Question 6

What is tail recursion in Scala and why is it important?

Accepted Answer

Recursion where the recursive call is the final operation, allowing stack optimization

Answer

Recursion on the last element

Answer

Recursion limited to tail collections

Answer

Recursion in companion objects