Kotlin

Join the Kotlin Track
Kotlin is a pragmatic programming language for JVM and Android that combines OO and functional features and is focused on interoperability, safety, clarity and tooling support.
Join the Kotlin Track
Track mentors

20 Mentors

Our mentors are friendly, experienced Kotlin developers who will help teach you new techniques and tricks.
Track students

8,590 Students

Join thousands of students who have enjoyed learning and improving their skills by taking this track.
Track exercises

84 Exercises

Hundreds of hours have gone into making these exercises fun, useful, and challenging to help you enjoy learning.

About Kotlin

fun getGreeting(): String {
    return "Hello, World!"
}

Kotlin was designed and developed by JetBrains, the company behind IntelliJ. It is a language that runs on the JVM which can target versions 6+ (including the Android platform). JetBrains wanted to use a statically typed language which can remove Java boilerplate code, provide modern functional paradigms, and had seamless two-way Java interoperability with their existing codebase. The JVM already had alternate languages like Groovy and Scala but neither fit the bill with their desired criteria, so they built Kotlin.

Kotlin syntax is similar to Scala and Swift but pulls in the best-of-breed features from other languages such as C# and Groovy. Kotlin took a pragmatic approach at features included in the language by only providing functionality that has been proven to be useful for developers. With this decision they implemented a subset of features of Scala with the intent that it will provide more maintainable code with an easier learning curve for developers looking for a "better Java".

JetBrains has a dedicated team of developers working on Kotlin with the codebase available on Github.

Join the Kotlin track

Exercism is a great website

The reviews are incredibly helpful because they help me see things that I missed, learn about new ways and sometimes interesting discussions that can add a fun twist to maybe a simple problem.

Relaxed. Encouraging. Supportive.

Meet the Kotlin Track mentors

Once you join the Kotlin language track, you will receive support and feedback from our team of mentors. Here are the bios of a few of the mentors of this track.

Avatar of Andrej

Andrej https://github.com/andrej-dyck

I love Kotlin for its simplicity and expressiveness. I've programmed in Kotlin professionally, and for me its the language that makes programming `fun` again ;).
Avatar of Derk-Jan Karrenbeld

Derk-Jan Karrenbeld https://github.com/SleeplessByte

After being stuck with Java for 8 years, Kotlin was the fresh breath of joy I needed.
Avatar of Adrian Spanu

Adrian Spanu https://github.com/aspanu

I work as a software engineer full time. Although I've never worked professionally in Kotlin, I've really enjoyed the language and I generally use it for interview problems or personal projects. I'm looking forward to helping others with it as I learn along myself.
Avatar of Sinuhe Jaime

Sinuhe Jaime https://github.com/sierisimo

I'm a geek doing a lot of things, including Kotlin. I've using the language for 3 years now but still learning everyday
Avatar of Will Madison

Will Madison https://github.com/willmadison

Passionate developer. Live long learner. Father. Geek. Frat Boy :). I've written Kotlin professionaly and it is truly a lovely and pragmatic language!
Avatar of Elena Parovyshnaia

Elena Parovyshnaia https://github.com/eparovyshnaya

Do respect Kotlin for been concise, expressive and for addressing most of the developer's everyday needs in such an elegant way.
Fun. Challenging. Interesting

Community-sourced Kotlin exercises

These are a few of the 84 exercises on the Kotlin track. You can see all the exercises here.

Run Length Encoding
easy
loops
regular expressions
strings
transforming
type conversion
Secret Handshake
easy
bitwise operations
conditionals
cryptography
enumerations
integers
loops
transforming
Nucleotide Count
medium
conditionals
exception handling
integers
maps
parsing
searching
strings
Space Age
easy
conditionals
floating point numbers
Prime Factors
medium
arrays
conditionals
integers
lists
loops
math
Robot Simulator
medium
classes
enumerations
logic
loops
Passionate. Knowledgeable. Creative.

Meet the Kotlin Track maintainers

The Kotlin Maintainers are the brains behind the Kotlin Track. They spend their spare time creating interesting and challenging exercises that we can all learn from. We are incredibly grateful for their hard work. Here are the bios of a few of the maintainers of this track.

Avatar of Mike Gehard

Mike Gehard

Long time software developer, recovering chemical engineer. I love helping folks along their path because I learn something new every time.
Avatar of Sam Warner

Sam Warner

I am a software developer and consultant working for Black Pepper Software, a software company based in Leamington Spa, England. I'm a recent Computer Science graduate from the University of Warwick, and love all things to do with computers!
Avatar of Denys M

Denys M

[Mobile] Software engineer and Kotlin enthusiast.
Avatar of Elena Parovyshnaia

Elena Parovyshnaia

Staying with Java since 1.0, currently a Kotlin fan. Experienced in explaining things. Eager learner. Enthusiastic in putting things in order, evolving an infrastructure and processes, easing work for a community.

Get started with the Kotlin track. As with everything on Exercism, it's 100% free!

Join the Kotlin Track