JavaScript

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JavaScript is a scripting language, primarily used for creating dynamic websites and programming web servers. It's a very popular language, and supports a variety of programming paradigms.
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Track mentors

117 Mentors

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

54,624 Students

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

103 Exercises

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

About JavaScript

export function hello() {
  return 'Hello, World!';
};

ECMAScript is the standard that defines JavaScript, a programming language that allows web pages to be dynamic. It is an interpreted language, which means that it doesn't need to be compiled: instead the interpreter (such as a web browser) will parse the code and turn it into code that their machine can run - suitable for creating dynamic websites that can run on any browser* on any computer*!

JavaScript is not only for use in the browser. JavaScript runtimes, such as NodeJS and deno allow you to write, launch and serve requests on webservers. Other frameworks, such as Electron use JavaScript to write cross platform applications for Windows, Linux and Mac OS. Mobile app development is also a possibility, utilising react-native, ionic and various others, with expo now allowing to target Android, iOS and the web, all at once.

ECMAScript has grown to be one of the world’s most widely used general purpose programming languages. It is best known as the language embedded in web browsers but has also been widely adopted for server and embedded applications." — ECMA International Language Specification

Starting with the 6th edition (commonly known as ES2015 or ES6) in 2015, a new edition of the standard will be released each year. The 6th edition was a major update which brought many enhancements over ES5, including notably template strings, expressive arrow function syntax, and cleaner syntax for defining classes.

But because new syntax and features are coming to JavaScript each year, support for these changes is often incomplete in current browsers and the latest node. This doesn't mean we can't use it. Tools such as Babel offer transpilation for most features, allowing us to write as if it's the future.

Note: This track supports the latest ECMAScript syntax via Babel and the @babel/preset-env plugin, and new experimental features are enabled with each update of that plugin, matching the release of the specifications. It automatically adapts to your local node installation. This means you don't need to worry about what is and isn't supported.


* There is a small number of browsers that doesn't ship with a JavaScript runtime, or that has disabled JavaScript execution by default.

Join the JavaScript 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 JavaScript Track mentors

Once you join the JavaScript 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 Shankar Shastri

Shankar Shastri GitHub Profile

Lover Of Pure Functional Programming.
Avatar of Daniel Couper

Daniel Couper https://github.com/DanCouper

I've programmed JS professionally for the last five years: sure, it has it's pain points, and the tooling/package management is somewhat of a hellscape, but on good days I kinda love it.
Avatar of Thomas Gamble

Thomas Gamble https://github.com/gambtho

Enjoy solving problems and helping others learn. I've written javascript professionally, and also use it for open source projects.
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 Frederic Charette

Frederic Charette https://github.com/fed135

Writing Javascript for Backend applications and open-source development are my passions. I’ve been coding for about 16 years now, and I feel that we’re probably living in one of the best possible times for Javascript software development.
Avatar of Georg Tavonius

Georg Tavonius https://github.com/Calamari

I am a professional freelance developer who mainly writes JavaScript and Ruby. And that almost every day. But I don't stop there. Currently I am also training myself in Rust & Go thanks to exercism.io.
Fun. Challenging. Interesting

Community-sourced JavaScript exercises

These are a few of the 103 exercises on the JavaScript track. You can see all the exercises here.

OCR Numbers
medium
equality
exception handling
integers
parsing
text formatting
conditionals
loops
Perfect Numbers
easy
arrays
integers
math
conditionals
loops
Sublist
medium
arrays
lists
Simple Linked List
hard
arrays
lists
data structures
Anagram
easy
filtering
strings
Isogram
easy
filtering
strings
Passionate. Knowledgeable. Creative.

Meet the JavaScript Track maintainers

The JavaScript Maintainers are the brains behind the JavaScript 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 Tejas Bubane

Tejas Bubane My blog

Primarily a Ruby & Javascript coder, getting better at functional programming, emacs lover.
Avatar of Derk-Jan Karrenbeld

Derk-Jan Karrenbeld My website

All-round programmer, manager and owner of a Dutch software agency specializing in bespoke and tailored code.

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