Java

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Java is a very widely used Object Oriented programming language. It's safe, simple to use and portable so that you can "write once, run anywhere".
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Track mentors

61 Mentors

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

22,625 Students

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

108 Exercises

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

About Java

class Greeter {

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

}

Java is among the most popular available programming languages, thanks to its versatility and compatibility. It is widely used for software development, mobile applications and developing larger systems.

Java was born in 1995 and is maintained by Oracle. Despite the fact that it isn't as young as some of the fresh languages out there, Java is still really popular. It was designed to be fast, secure, reliable, beginner-friendly and highly portable. This portability perk exists because Java is executed on a cross-platform compatible Java Virtual Machine - JVM. Android apps are also developed using Java, since the Android Operating System runs on a Java language environment.

The Java community is huge! GitHub for example has over 1.5 million Java projects. It's also worth mentioning that Java has the second largest community in StackOverflow! This is important because the larger a programming language community is, the more support you'd be likely to get.

Java also has a powerful and well-designed set of built-in APIs - Application Programming Interfaces, which can be used for various activities like Database connection, networking, I/O, XML parsing, utilities, and much more.

From laptops to datacenters, game consoles to scientific supercomputers, cell phones to the Internet, Java is everywhere!

Join the Java track

Exercism is a great website

What I like about it is that I am able to solve the challenges in a TDD way working in a environment that I am familiar (my own PC not a browser IDE) and the cherry on the top of the cake is that I have access to code reviews.

Relaxed. Encouraging. Supportive.

Meet the Java Track mentors

Once you join the Java 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 Lorenzo Addazi

Lorenzo Addazi https://github.com/loradd

I am a researcher in model-driven engineering and domain-specific languages with a pure love for programming.
Avatar of Marcus Bergenlid

Marcus Bergenlid https://github.com/mbergenlid

I'm a software engineer working professionally in Java, I love to learn new languages and to improve my coding style. My side projects are usually focused around learning some new language or technology.
Avatar of Dennis Hartrampf

Dennis Hartrampf https://github.com/DennisHartrampf

I have 7+ years experience as software developer, mainly using Java, recently also Kotlin ♥. I'm a fast learner and eager to explore new technologies. I'm also a believer in agile software development, team work and Clean Code.
Avatar of Rahmeen Habib

Rahmeen Habib https://github.com/Rahmeen14

I write C++ at the university, have 10 week professional experience with Java in an intern project and am an RGSoC scholar for a JavaScript Project
Avatar of Zuzanna Kru

Zuzanna Kru https://github.com/zuzia-kru

I have been working with Java professionally for almost 4 years now and I'm particularly passionate about the functional style features of it like the Stream API.
Avatar of Daria Golub

Daria Golub Twitter

I am a software developer, with the main focus on Java. Clean code, proper tests, best practices ♥.
Fun. Challenging. Interesting

Community-sourced Java exercises

These are a few of the 108 exercises on the Java track. You can see all the exercises here.

Minesweeper
medium
conditionals
games
integers
lists
matrices
strings
Custom Set
hard
equality
generics
sets
Robot Name
medium
pattern matching
randomness
regular expressions
strings
text formatting
Luhn
medium
algorithms
booleans
loops
strings
type conversion
Reverse String
easy
strings
Sieve
medium
algorithms
integers
lists
loops
math
Passionate. Knowledgeable. Creative.

Meet the Java Track maintainers

The Java Maintainers are the brains behind the Java 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 Anna Weber

Anna Weber

I used to be a health economist, and am now on my way to becoming a software engineer. Exercism's Java track got me started with open source.
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 Frida Johanne Tveit

Frida Johanne Tveit

I'm a software developer working for Softwire, a UK based software company. I'm a full stack developer working with many different languages including Java. I love programming and helping other people learn more about it!
Avatar of Logan Stucki

Logan Stucki Sometimes I blog on my site

I'm a 17 year old student and code artisian. I love writing code and making things. Currently, I enjoy answering stackoverflow questions and making webapps when not contributing to exercism.
Avatar of Jason Runkle

Jason Runkle

I have been writing Java code professionally for the past 3 years and I have had a wonderful experience with it. The functional style of Java 8 took some getting used to, but it really improved my team's codebase and productivity.

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

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