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

122 Mentors

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

61,571 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

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 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 Naresh Thakur

Naresh Thakur https://github.com/thakurinbox

I work as a senior full stack engineer. Mostly I worked with JavaScript in my career. I usually work on Node, React/Redux. And I can work on any JavScript library or framework. I love so solve logical problems. I am here to help to get familiar with data structures and algorithms
Avatar of Edouard Souan

Edouard Souan

I write javascript and other languages professionally. I love to learn and share with others.
Avatar of Brandon A Welsh

Brandon A Welsh https://github.com/BrandonArmand

Javascript is the first line of defense! Reach out to me and get in touch with any questions or collaborations, I love to network and help.
Avatar of Dagmar Timmreck

Dagmar Timmreck https://github.com/DagmarTimmreck

JS - or better ES6 - is my main language at work. I am a mathematician by training, sing in a semi-professional choir and am a mother of three.
Avatar of Ian Fosbery

Ian Fosbery https://www.codeguy.io

I've been a programmer for over 15 years. My day-to-day lately has been JS everywhere. Everywhere. I've really gotten into functional programming in recent years, which is how I tend to write Javascript. But, it can be written in many different ways and it's all about the context.
Avatar of Sean Fairchild

Sean Fairchild https://github.com/sfairchild

I'm a senior Ruby dev professionally at my company. I have also worked a lot with JavaScript and most recently lead a team building a React app for one of our clients.
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.

Binary Search Tree
medium
algorithms
recursion
conditionals
loops
Custom Set
medium
arrays
equality
lists
recursion
sets
conditionals
loops
data structures
Phone Number
easy
parsing
transforming
Linked List
medium
algorithms
arrays
lists
optional values
conditionals
loops
data structures
Allergies
medium
arrays
bitwise operations
conditionals
loops
Crypto Square
hard
algorithms
arrays
regular expressions
sorting
text formatting
transforming
conditionals
loops
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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Join the JavaScript Track