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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

76 Mentors

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

50,236 Students

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

114 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!

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A tremendous learning opportunity to explore the depth of your own knowledge

Exercism is fantastic in learning new languages but that is not the extent of it. If you are a "more experienced" programmer you may have encountered impostor syndrome: the idea you don't really know what you think you know. Exercism lets you solve problems and put them in the space of open feedback which is a tremendous learning opportunity to explore the depth of your own knowledge. Even if you have been programming in a language for awhile it is worth checking into Exercism to see where you stand with current implementation practices.

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 Bastien Lemale

Bastien Lemale https://github.com/blemale

I've been working professionally with Java for about 5 years from web development to data processing. I've also written Scala professionally, and also use it for open source projects. And finally I'm a Rust enthusiastic.
Avatar of Koen Wellens

Koen Wellens My blog where I review books.

I've been working with Java for about 10 years now. I think I've come at a level where I can help others.
Avatar of Karim DRIDI

Karim DRIDI My LinkedIn Profile

Passionate about coding since 1995.
Avatar of Maisam Somji

Maisam Somji https://github.com/msomji

I'm a full stack developer with a love for all things related to functional programming. I spend the bulk of my time solving complex problems using simple but not necessarily easy solutions.
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 Sébastien NEDJAR

Sébastien NEDJAR https://github.com/nedseb

I'm an associate professor at Aix-Marseille University. I've written et taught Java and C/C++ professionally. I love learning new languages especially functional ones.
Fun. Challenging. Interesting

Community-sourced Java exercises

These are a few of the 114 exercises on the Java track. You can see all the exercises here.

Alphametics
medium
conditionals
logic
All Your Base
medium
arrays
conditionals
exception handling
integers
loops
math
Sieve
medium
algorithms
integers
lists
loops
math
Change
hard
algorithms
exception handling
integers
lists
Two Fer
easy
conditionals
strings
Rail Fence Cipher
medium
conditionals
loops
strings
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 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 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!

Join the Java Track