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What Is JavaScript Used For?

Learn more about one of the world’s most popular programming languages.

What Is JavaScript Used For?

JavaScript is a text-based scripting language or programming language used on both the server-side and client-side to create engaging website elements, fully featured web applications, CLI applications and even web servers. In short, JavaScript is extremely versatile.

Where the HTML and CSS programming languages are used to give websites their structure and style, JavaScript is used to take static web applications and brings them to life, greatly improving the user experience in the process.

Uses of JavaScript

Given how popular and ubiquitous JavaScript has become, it sometimes seems like the answer to the question “What is JavaScript used for?” is “everything.”

Here are a few of the top uses of JavaScript:

Making web pages interactive

If you ask most professionals in web development, JavaScript is principally used for making web apps and web technologies more dynamic, visually appealing, intuitive, and pleasing to use.

JavaScript code is a crucial part of front-end web development, giving Web Developers the power to add any number of interactive elements that can add rich graphics, visual flair, and helpful usability features to what would otherwise be lifeless web content.

Here are just a few of the JavaScript uses when it comes to web development:

  • Creating buttons that will respond to a hovering mouse cursor. This can include changing color or showing or hiding additional information
  • Embedding Google search boxes, YouTube videos, or scrolling multimedia playlists
  • Allowing users to zoom in or zoom out on images or other content on the page
  • Loading documents for a user without having to reload the entire web page
  • Creating a variety of interactive menus, including drop-downs, hamburger menus, and more
  • Displaying animations on the web page
  • Validating data entered into websites for sign-up forms

Creating web and mobile applications

JavaScript is one of the most popular languages to build websites, web applications, and mobile apps.

JavaScript frameworks are collections of JavaScript libraries that feature pre-written code, which can save Developers lots of time when it comes to completing basic web and software development tasks, making it much easier to build dynamic, interactive web apps and mobile applications. These frameworks allow for predictability and maintainability, both of which allow for scalable, healthy software that can last long-term.

Popular JavaScript frameworks include React, React Native, Angular, and Vue. You may have heard of Node.js in the context of JavaScript frameworks, but it is actually not considered a framework. It is, in fact, a JavaScript runtime environment, which is a set of components used to create and run a JavaScript application.

When working with JavaScript, particularly for client-side web applications, you will likely use an application programming interface (API), which is a type of software interface that connects computers and computer programs. Application programming interfaces are built on top of core JavaScript, giving your code extra flexibility and power.

Typically, there are two types of APIs:

  • Browser APIs

Browser APIs are built into web browsers and can do complex things (like audio processing and effects) with the data from the browser and surrounding computer environment.

  • Third-party APIs

Third-party APIs are, by contrast, not built into a browser and you have to get their information from a third-party online. Most social media platforms, for example, will have their own API, allowing you to display things like posts and tweets on web pages.

Building web servers

Developers can also use JavaScript to build web servers, using Node.js to develop back-end infrastructure. If you’re not sure what that means, the front-end in development involves the presentation of content (including stylistic elements like colors and navigation), with the back-end charged with handling how data and information are processed and stored.

Creating games

JavaScript can also be used to create browser games and has been the basis for many basic online games over the years.

The programming language is, in fact, a good way to get started with web game development, as knowledge of JavaScript allows you to choose a framework that can really speed up the process.

What Does JavaScript Do?

In simplest terms, what JavaScript does is add automation, animations, and interactivity to web applications and pages. That last bit is important: JavaScript is a client-side programming language, which means that a web browser (or client) reads, interprets, and executes JavaScript scripts. This differs from a server-side programming language, which has to run on a remote computer, like a server.

What Does JavaScript Do in the Browser?

As a client-side programming language, JavaScript allows Developers to do the following in the browser:

Automate simple tasks

JavaScript can be used to optimize web pages, develop greetings, customize page footers, and more.

Make changes instantly

Unlike some other programming languages, Javascript is “event-driven” allowing it to respond to events like a keyboard input or web page input. It also has access to the Document Object Model (DOM), giving it access to change fonts, images, text, form fields, and other web page elements. These two features let Developers perform a number of tasks, including implementing interactive features, such as image sliders and games.

Communicate with a server

Using Ajax, Javascript can access computing power and resources that would be impossible through a purely client-side application. This greatly increases its flexibility for web development and mobile applications, giving Developers the tools to create powerful web applications.

What Does JavaScript Do Outside the Browser?

JavaScript can also run outside the browser using runtimes like node.js, deno, or bun. This means that Developers can use JavaScript as a general purpose programming language to build things like CLI tools, web servers, data analytics applications, automation scripts, testing applications, and using frameworks like Electron or React Native, JavaScript can even be used to create cross-platform desktop applications and native mobile applications.

How to Use JavaScript

You can use JavaScript to make website apps and apps for mobile devices more interactive. Do you want to see this in action? You won’t have to look far. Just think of what happens when you select an item on a dropdown menu as just one of many JavaScript examples, and you have a good idea of how JavaScript allows things to change on a website.

You can use JavaScript to add new, engaging features to your site, which can improve the user experience and help attract new visitors. More importantly, perhaps, is that Developers can save time with JavaScript, implementing rich web applications with additional software or browser add-ons.

Is JavaScript a Programming Language?

Yes, JavaScript is one of the most popular and commonly used programming languages.

To be more precise, JavaScript is a scripting, text-based programming language that is used to add dynamic elements in web development, web applications, game development, and more. Together with HTML and CSS, it forms a key trio of standard web technologies; the building blocks of a website.

JavaScript gives you the ability to add dynamic elements on a web page (meaning more than just static information), which can include video, interactive maps, animated graphics, and more.

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