SKB – Scala Repeated Parameters


This article is part of the Scala knowledge bits Series.

Periodically, I will publish new exercises so you can slowly build up knowledge about Scala.

It is designed to be done in a very short amount of time and learn a little bit each day, just to create a routine.

This episode will teach you about Scala Repeated Parameters.

Hope you are going to enjoy it! It is designed for anyone to learn Scala from scratch and slowly learn, one Bit at a time.

After this Bit, I would love to hear your feedback in the comments down below.

Feel free to join the Discord server as well if you would like some help and support from the rest of our community.

What are we learning today?

Today we are going to learn about Scala Repeated Parameters !

Little break in Object Oriented Programming and Functional Programming features.

Today is about a little “nice to know”.

Time to try on the exercise on your own and scroll down for more information when you are done or if you are stuck.


Here is an exercise to complete today.

If I did my job well, you should be able to guess by yourself the solution based on what you previously learned and based on the clues.

But if you get stuck, scroll down to get more information.

The goal of the exercise is to replace the ??? by a piece of code so that the exercise compiles and that’s how you win! Good luck!

You can fill the exercise right in here:

Or, if it does not load, go on to Scastie (t4txyXUBQ16HDTrla2PhZw).

More information about Scala Repeated Parameters

In this exercise you will learn (or have learned, if you have already solved the puzzle) about Scala Repeated Parameters.

You probably understood that this allow you to take an array as input without having to actually create an array when calling the function.

It can be very useful with nested case class with list of list. It makes the code more readable.

case class Foo(f: Foo*)

Imagine this code with having to create List(Foo()) each time, it would make the code really hard to digest.

But, like everything in life, there is a drawback… If you already have an array, you need to use the weird :_*. It is a minor issue, with experience, you are going to know those few characters by heart. It basically turns a list of item into a series of arguments.

Feel free to go back to the exercise, modify the code to try out new things and get a better intuition for Scala Repeated Parameters.


I hope you have learned something new or had fun during this Scala Knowledge Bit.

Please ask questions or post feedback in the comments below.

Feel free to try on the next Scala Knowledege Bit.

If you are curious about the previous Scala knowledge Bits, go check it out! 🙂

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