What is Javascript Used For?
Javascript and HTML book

JavaScript is arguably the most universal programming language of the web. Today it is considered a mandatory language to learn and use as a developer, and thanks to its versatility in the tech sector, JavaScript’s influence continues to grow.   

So, what makes JavaScript a leading language? Here’s what you should know about this foundational tool and why it’s one of the top skills full stack web developers need in 2021.

What is JavaScript?

Created in 1995, JavaScript is a text-based open-source scripting and programming language used to make websites more interactive. Known for its security and portability to run on virtually any operating system, it has the ability to insert dynamic text right into a web page’s HTML and run automatically as the page loads.

JavaScript is not only used to write frontend and backend code for servers to make websites more intuitive, but it is used on both the client-side and server-sides of a website, making it a truly versatile tool used across devices and platforms. Additionally, JavaScript executes in the browser, but can be used on a server with the help of a JavaScript engine.

First called LiveScript, JavaScript rebranded as another beloved programming language Java grew in popularity. By name, Java and JavaScript may sound similar, but these object-oriented programming (OOP) languages are not related. In fact, they have very little in common aside from being popular, versatile, and used in front-end and back-end development. So, what’s the difference between Java and JavaScript? Java is a general-purpose OOP compiling language using platform-independent programming executed in the Java Virtual Machine (JVM), while JavaScript is an OOP scripting language used to create dynamic HTML pages. Aside from the fact that JavaScript is easier to learn, the biggest difference is in the code itself. Java code must be compiled, while JavaScript code is all in text.  

What is JavaScript used for?

JavaScript makes a website’s user interface easier to navigate and makes web pages more interactive and engaging. That’s why it’s used by tech giants Google, Facebook, Amazon, YouTube, and Twitter to give static information more functionality and make it come to life with 2D/3D graphics, animated images, interactive pop-up videos, interactive maps, and real-time content updates.

If JavaScript, HTML, and CSS together form the building blocks of front-end web development, JavaScript is there to bring the fun. Consider this – when you load a webpage in your browser you are running code like JavaScript, CSS, and HTML to create the interface you see and interact with. JavaScript can then be used to modify the CSS and HTML components through Document Object Model API, allowing a programmer to manipulate HTML and CSS and display more interactive content like pop-up windows, drop down menus, count-down timers, animations, scrolling videos, and more.

JavaScript not only helps developers create web applications, it can also create browser games, build simple web servers, complete front-end coding using Angular, and develop back-end infrastructure using Node.js. JavaScript most commonly runs code in response to webpage or application events, operates on pieces of text known as “strings”, and stores useful values inside variables. JavaScript is even used in unexpected places outside of the internet, including iOS and Andriod apps, cross platform desktop apps, smart TV’s, and even works with the Internet of Things (IoT). 

Why learn JavaScript? 

JavaScript is a programming favorite – and for good reason. Over the last decade, JavaScript has become a foundational web technology along with HTML and CSS. Although it can be useful to learn HTML and CSS first, developers will also add frameworks to JavaScript like Angular, React.js, or Vue.js in the frontend and Node.js in the backend to complete projects. Further, since it works on most browsers and is now used in app development, desktop app development, and game development, JavaScript’s relevance will only increase with demand.

Hired’s 2020 State of Software Engineers report shows that 63% of software engineers use JavaScript, making it the most commonly used programming language of software engineers by almost 20%. Not only is JavaScript utilized in 95% of all websites, it is the standard programming language of all major web browsers.

Finally, companies looking for JavaScript professionals are willing to pay well. The average JavaScript Developer Salary in the United States in 2021 is $109,807. It’s no wonder, then, that JavaScript is taught at most full stack web app development programs including Lambda School because of its staying power, versatility, and return on investment.  

How can I start learning JavaScript? 

Ready to jump in and learn JavaScript? At Lambda School, we immerse aspiring developers in the foundational skills needed in the field. Our Full Stack Development Course dives deep into all the languages and technologies needed to build and maintain any website from the ground up, including JavaScript, HTML, CSS, React, Python, and more.

Ready to dive into JavaScript and start learning front end web development? Lambda School’s Full Stack Development Course is here for you. Interested in other programming languages like Java? Try our newest Backend Web Development Course. Curious about dipping your toe into the fundamentals? Begin your journey with Lambda School’s free Intro to HTML and CSS Course. No matter where you start, we’re ready to support your dream!

Learn more about our highly competitive pay-nothing-upfront tuition options by applying for a full-time course today.


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