JavaScript Tutorial

This JavaScript tutorial has been designed for beginners as well as working professionals to help them understand the basic to advanced concepts and functionalities of JavaScript. It covers most of the important concepts related to JavaScript such as operators, control flow, functions, objects, OOPs, Asynchronous JavaScript, Events, DOM manipulation and much more.

What is JavaScript

JavaScript is a lightweight, interpreted programming language. It is commonly used to create dynamic and interactive elements in web applications. JavaScript is very easy to implement because it is integrated with HTML. It is open and cross-platform.

Why to Learn JavaScript?

JavaScript is a MUST for students and working professionals to become a great Software Engineer, especially when they are working in Web Development Domain. We will list down some of the key advantages of learning JavaScript−

• JavaScript is the most popular programming language in the world, making it a programmer's great choice. Once you learn JavaScript, it helps you develop great front-end and back-end software using different JavaScript based frameworks like jQuery, Node.JS, etc.
• JavaScript is everywhere, it comes installed on every modern web browser and so to learn JavaScript, you really do not need any special environment setup. For example, Chrome, Mozilla Firefox, Safari, and every browser you know as of today, supports JavaScript.
• JavaScript helps you create really beautiful and crazy fast websites. You can develop your website with a console like look and feel and give your users the best Graphical User Experience.
• JavaScript usage has now extended to mobile app development, desktop app development, and game development. This opens many opportunities for you as JavaScript Programmer.
• Due to high demand, there is tons of job growth and high pay for those who know JavaScript. You can navigate over to different job sites to see what having JavaScript skills looks like in the job market.
• Great thing about JavaScript is that you will find tons of frameworks and Libraries already developed which can be used directly in your software development to reduce your time to market.
• JavaScript is in all over the world, and companies like Google, Meta, Microsoft, PayPal, LinkedIn, etc. also use JavaScript.
• Furthermore, JavaScript has more than 1.5 lakh libraries. It is also growing.
• A huge community of JavaScript is available on the internet with students, developers, and mentors. So anyone can easily get support.

There could be 1000s of good reasons to learn JavaScript Programming. But one thing for sure, to learn any programming language, not only JavaScript, you just need to code, and code, and finally code until you become an expert.

JavaScript Applications

As mentioned before, JavaScript is one of the most widely used programming languages (Front-end as well as Back-end). It has its presence in almost every area of software development. I'm going to list few of them here:

• Client side validation − This is really important to verify any user input before submitting it to the server and JavaScript plays an important role in validating those inputs at front-end itself.
• Manipulating HTML Pages − JavaScript helps in manipulating HTML page on the fly. This helps in adding and deleting any HTML tag very easily using JavaScript and modify your HTML to change its look and feel based on different devices and requirements.
• User Notifications − You can use JavaScript to raise dynamic pop-ups on the webpages to give different types of notifications to your website visitors.
• Back-end Data Loading − JavaScript provides Ajax library which helps in loading back-end data while you are doing some other processing. This really gives an amazing experience to your website visitors.
• Presentations − JavaScript also provides the facility of creating presentations which gives website look and feel. JavaScript provides RevealJS and BespokeJS libraries to build a web-based slide presentation.
• Server Applications − Node JS is built on Chrome's JavaScript runtime for building fast and scalable network applications. This is an event based library which helps in developing very sophisticated server applications including Web Servers.
• Machine learning − Developers can use the ML5.js library to complete the task related to machine learning.
• Game Developments − JavaScript contains multiple libraries and NPM packages to design graphics for the game. We can use HTML, CSS, and JavaScript with libraries to develop the games.
• Mobile applications − We can use frameworks like React Native to build feature-rich mobile applications.
• Internet of Things (IoT) − JavaScript is used to add functionality to devices like smartwatches, earbuds, etc.
• Data visualization − JavaScript contains the libraries like D3.js to visualize the data efficiently. The D3.js is also used to prepare high-quality charts to visualize the data.
• Cloud computing − We can use JavaScript in serverless computing platforms like Cloudflare and AWS lambda to write and deploy functions on the cloud.

This list goes on, there are various areas where millions of software developers are happily using JavaScript to develop great websites and other software.

Basic JavaScript Example

Below is a basic JavaScript example that will print "Getting started with JavaScript tutorial" on the webpage. You can edit this example and execute it by clicking on the "Edit & Run" button.

<script>
    document.write("Getting started with JavaScript tutorial");
</script>

Online JavaScript Editor

We have provided JavaScript Online Editor which helps you to Edit and Execute the code directly from your browser. Try to click the icon to run the following JavaScript code to print conventional "Hello, World!".

Open JS Editor to practice your scripts here

Below code box allows you to change the value of the code. Try to change the value of Hello, World! and run it again to verify the result.

<html>
   <head>
      <title>The JavaScript Example</title>
   </head>
   <body>
      <script language = "javascript" type = "text/javascript">
	     document.write("Hello World!")
      </script>
   </body>
</html>

Who Should Learn JavaScript?

This JavaScript tutorial has been prepared for student as well as working professionals to help them understand the basic functionality of JavaScript to build dynamic web pages and web applications.

Prerequisites to Learn JavaScript

For this JavaScript tutorial, it is assumed that the reader has prior knowledge of HTML coding. It would help if the reader had prior exposure to object-oriented programming concepts and a general idea of creating online applications.

JavaScript Online Quizzes

This Javascript tutorial helps you prepare for technical interviews and certification exams. We have provided various quizzes and assignments to check your learning level. Given quizzes have multiple choice type of questions and their answers with short explanation.

Following is a sample quiz, try to attempt any of the given answers:

Start your online quiz Start Javascript Quiz.

JavaScript Jobs

In the world, there are 15+ Million active JavaScript developers. Still, there is a shortage of skilled JavaScript developers. So, it could be a great chance for you to start your career as a JavaScript developer.

Here are the most popular companies offering the role of JavaScript developer. You can land as an employee with a high package after pursuing your career as a JavaScript developer.

• Amazon
• Google
• Microsoft
• Apple
• Adobe
• Facebook
• PayPal
• Many more...

Careers Opportunities in JavaScript

There are several career paths that you can choose after learning JavaScript. Here, we have listed some of them.

• Front-end developer
• Back-end developer
• Full-stack developer
• Web developer
• Game developer
• Mobile App developer
• DevOps Engineer
• Many other roles

JavaScript Frameworks and Libraries

JavaScript frameworks are used to develop a whole application. It defines the structure of your application.

The framework can have pre-built components and other functionalities that can help you reuse the code of the application, improve code readability, and avoid duplicity.

Here, we have explained the most popular JavaScript frameworks which you can use for website development, app development, backend development, etc.

• React
• Angular
• Vue.js
• Ember.js
• Node.js
• Backbone.js
• Next.js
• Mocha
• Meteorjs
• Polymer

In JavaScript, a library is a set of pre-defined functions, classes, methods, objects, etc. You can import the library in your JavaScript code by using the CDN or downloading it locally. After adding the library to the project, you can use the library's pre-written functions, classes, etc., in the code.

Here, we have given a list of the most popular JavaScript libraries.

• jQuery
• Axios
• Chart.js
• D3.js
• Socket.io
• Underscore.js
• Lodash
• Three.js

JavaScript Certification

Get certified in JavaScript to boost your skills and career

JavaScript Practice

To practice and quick revision of JavaScript, we also provided:

• JavaScript Interview Questions
• JavaScript Quick Guide
• JavaScript Cheatsheet
• JavaScript Built-in Functions

JavaScript Articles

You can explore a set of JavaScript Articles at JavaScript Articles.

Frequently Asked Questions about JavaScript

There are some very Frequently Asked Questions(FAQ) about JavaScript, this section tries to answer them briefly.

JavaScript is a lightweight, interpreted programming language with object-oriented capabilities that allows you to build interactivity into otherwise static HTML pages.

The general-purpose core of the language has been embedded in Netscape, Internet Explorer, and other web browsers.

Following are the features of JavaScript −

• JavaScript is a lightweight, interpreted programming language.
• JavaScript is designed for creating network-centric applications.
• JavaScript is complementary to and integrated with Java.
• JavaScript is is complementary to and integrated with HTML.
• JavaScript is open and cross-platform.

Following are the advantages of using JavaScript −

• Less server interaction − You can validate user input before sending the page off to the server. This saves server traffic, which means less load on your server.
• Immediate feedback to the visitors − They don't have to wait for a page reload to see if they have forgotten to enter something.
• Increased interactivity − You can create interfaces that react when the user hovers over them with a mouse or activates them via the keyboard.
• Richer interfaces − You can use JavaScript to include such items as drag-and-drop components and sliders to give a Rich Interface to your site visitors.

We can not treat JavaScript as a full fledged programming language. It lacks the following important features −

• Client-side JavaScript does not allow the reading or writing of files. This has been kept for security reason.
• JavaScript can not be used for Networking applications because there is no such support available.
• JavaScript doesn't have any multithreading or multiprocess capabilities.

Yes! JavaScript is a case-sensitive language. This means that language keywords, variables, function names, and any other identifiers must always be typed with a consistent capitalization of letters.

You can use our simple and the best JavaScript tutorial to learn Java and Advanced Java. We have removed all the unnecessary complexity while teaching you Java concepts. You can start learning it now Start Learning JavaScript.

Some backend JavaScript frameworks are listed as below −

• Express
• Next
• Gatsby
• Meteor