Scala Functional Programming in Scala 1

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 pure function always produces the same output for the same input and does not cause any observable side effects.

Question 2

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

Accepted Answer

map

Answer

`map` transforms each element of a collection by applying a function and returns a new collection of the results.

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

Higher-order functions accept functions as arguments or return functions, enabling powerful functional composition patterns.

Question 4

Which operator is used for function composition in Scala?

Accepted Answer

andThen or compose

Answer

Scala's `Function1` provides `compose` and `andThen` methods to chain functions together in different orders.

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` applies a function that returns a collection to each element and then flattens all results into a single collection.

Scala Practice Test