Kotlin

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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.
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Track mentors

19 Mentors

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

6,937 Students

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

85 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

Exercism is a great website where I was able to have some very interesting challenges.

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 Alex Ahern

Alex Ahern https://github.com/aahern

I work as an Android developer on one of the oldest apps in the UK Play Store. We have been using Kotlin as our primary language for around a year now, and I'd like to help others develop their skills while at the same time developing my own.
Avatar of James Landrum

James Landrum James Landrum

I jumped on the Kotlin train back in 2014 after learning about it being a better alternative to the awesome RetroLambda and have been a massive fan since.
Avatar of Gurpreet Singh

Gurpreet Singh Website

I am an Android Developer based out of New Delhi, and have been working with Kotlin for over a year. I'm particularly interested in Functional & Reactive programming paradigm and like to share my knowledge and learn from others.
Avatar of Jacob Andersen

Jacob Andersen https://github.com/simpleauthority

I've been using Kotlin for smaller projects for about a year. I find its simplicity and expressive nature very refreshing. I'm ready to help you bring your Kotlin skills to the next level.
Avatar of Lidonis Calhau

Lidonis Calhau https://github.com/lidonis

I have been a web developer for quite some time. I really like Kotlin because it's design the way a would write a new OO language. I hope we can learn it a little bit better on this track.
Avatar of Mike Gehard

Mike Gehard My musings on software.

I love writing Kotlin because it has some of the power of Scala without all of the type system complexity. It is a breath of fresh air in the Java ecosystem for those of us that like the JVM but don't like Java.
Fun. Challenging. Interesting

Community-sourced Kotlin exercises

These are a few of the 85 exercises on the Kotlin track. You can see all the exercises here.

Spiral Matrix
medium
arrays
integers
loops
matrices
Hamming
easy
integers
loops
strings
Resistor Color Trio
easy
math
type conversion
lists
Secret Handshake
easy
bitwise operations
conditionals
cryptography
enumerations
integers
loops
transforming
Triangle
medium
conditionals
exception handling
integers
recursion
Yacht
easy
enums
functional programming
lists
pattern matching
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 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.
Avatar of Denys M

Denys M

[Mobile] Software engineer and Kotlin enthusiast.
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!

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