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What is JavaScript used for? 7 practical JavaScript uses

Find out some of the top uses for JavaScript, as we explore why it’s such a popular and diverse programming language.

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If you’d like to get to grips with programming on the internet, then fluency in JavaScript is sure to be worthwhile. Along with HTML and CSS, it’s fundamental to how modern webpages work — and it can do a whole lot more, besides.

In this article, we take a closer look at some of the uses of JavaScript as well as why it’s such a popular and versatile programming language.

JavaScript – the basics

Before we get into the details of what you can do with JavaScript, let’s get some of the essentials out of the way. If you’re hoping to learn a programming language, these basics can help you understand why JavaScript could be an excellent choice.  

What is JavaScript?

JavaScript came about in the early 90s when Internet Explorer and Netscape Navigator were the most popular browsers. A Netscape employee named Brendan Eich developed a programming language that would allow the browser to respond to commands from the user. He called it LiveScript.

The script was renamed in order to piggyback off the reputation of Java, another popular programming language that was prominent at the time. However, it needed a separate special plugin to run.

So, what’s the difference between Java and JavaScript? Both of them are highly technical. Java tends to be used more in servers than on client machines such as phones, desktops and laptops. JavaScript is run on an internet browser, like Chrome or Firefox. What’s important is that they’re not to be confused!

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Why is JavaScript so popular?

The TIOBE Index puts Javascript as the seventh most popular programming language, just between PHP and Visual Basic. It’s a little more niche than Python, C and Java, but it offers several key advantages which set it apart. Let’s consider a few of the more noteworthy.

  • High level. JavaScript is a high-level language, much like Python and C. This basically means that it’s easy for human beings to read, especially if they’ve programmed in other languages.
  • Established. JavaScript has been around in one form or another for more than three decades. As such, there are plenty of resources around for new users to get stuck into, and plenty of existing expertise available.
  • No compilation. JavaScript can be executed as soon as it’s written, without the need for compiling. This allows for much speedier prototyping, and, frankly, much less irritation. 
  • Versatility. Over the years, JavaScript has accumulated a whole range of extra features thanks to ‘libraries’ of functions that can be appended as required. As such, you can use JavaScript for pretty much everything.
  • Lower overheads. JavaScript is well-optimised, meaning that anything you create with it will tend to run smoothly on a whole range of different machines.
  • Interoperability. If you’ve developed an entire website in a different programming language, then it’s usually no trouble to simply insert additional content in JavaScript.

Why learn JavaScript?

Aside from the fundamental strengths we’ve already outlined, there are good career-based reasons for developers to pick up JavaScript.

  • It’s in high demand among employers. As such, you’ll never be short of work.
  • It’s lucrative. In the UK in 2022, the median annual salary for a JavaScript developer was around £60,000 – which is an increase over previous years. 
  • It’s established. This not only means that there are plenty of resources around for students, but that you can be sure of job security for years to come.

What are some JavaScript essentials?

Javascript uses a handful of fundamental building blocks, and we’ll explain some of the most important things you can do below.

  • JavaScript function. A function is a set of statements that performs a particular task. They’re a great way to clean up your code and prevent redundancy: you can define a function just once, and then recall it wherever necessary.
  • JavaScript array. Arrays are an easy way of inserting lists into your program, and then retrieving specific elements of that list whenever you like. They’re fundamental, and you’ll be using them a lot! 
  • JavaScript map. The ‘map’ method provides a powerful means of rearranging arrays. It allows your list to be transcribed into another list, often with just a single line. 
  • JavaScript download. You can also use JavaScript to download files, which is very useful when you’re trying to retrieve external data, or instruct the browser to retrieve a file on the user’s behalf.

How is JavaScript used in web design?

As we pointed out in our overview of programming languages, JavaScript tends to be used whenever there’s a web browser involved. But it’s rarely used in isolation; it’s more often found alongside HTML and CSS. The three languages complement each other well, and so for best results, it’s best to have at least a slight grasp of all of them.

What is HTML?

Hypertext Markup Language is the code used to create most websites on the internet. It’s not a programming language, but rather a set of instructions on how to arrange special building blocks called elements. You can learn about them in our open step about HTML structure. Every element can be modified using special fields called attributes, which is explained further in our HTML attributes open step.

What is CSS?

During your travels in web design, you might have come across the term ‘CSS’. This term stands for Cascading Style Sheets, and, alongside HTML and JavaScript, it is crucial to the way that the modern web works. It’s easier to change a font setting in a CSS document than it is to go through an entire website, fiddling with every single page.

If you’d like to get going with either HTML or CSS, then our introduction is a great place to start. If your focus is on web-coding, then our Learn to Code for the Web course from the University of Leeds and Institute of Coding might also appeal. 

What is JavaScript used for?

Javascript can be used for things that don’t involve web browsers at all. Let’s take a look at some of the places you might decide to use it.

1. Mobile Apps

Thanks to some of the frameworks we’ve already touched on, JavaScript developers can create products for both iOS and Android using the same basic skill set. Creating Android games is usually an excellent place for aspiring developers to get started.

2. Interactive maps

JavaScript is perfect when it comes to creating maps. They can be zoomable and overlain with information about given locations. JavaScript can even be used to create maps of locations that don’t exist in the real world!

3. Virtual reality

VR is a relatively new and exciting field, with limits that are only just beginning to be explored. It’s being used by everyone, from gamers to surgeons to interior designers. JavaScript offers a powerful means of working with VR;  if you’d like to see how, you can check out our course on How to Construct a Virtual Reality Experience, from Lancaster University.

4. Booking systems

If you need guests at a restaurant to be able to book a table for a given time, then you’re probably going to be breaking out some JavaScript.

You might even present an interactive plan of a restaurant, indicating which tables are open at what time. The same advantages apply to cinemas, theatres, theme parks and just about every other attraction.

5. Games

Browser-based games are possible with the help of JavaScript. They don’t even have to be two-dimensional games — just about everything is possible. If you’re looking into web-based games or any type of software development, then check out our course on Software Development Fundamentals: Programming Languages and HTML

If you’d like a more focussed look at game design, you might alternatively consider Video Game Design and Development, or the Raspberry Pi Foundation’s Create Your Own Adventure Game.

6. Animations

If you need visual elements to move around, then Javascript will help you to do it. Javascript animations are very lightweight and can be tweaked to suit the displaying device. Animations can also be interactive — and infinitely zoomable.

7. Data visualisation

In our article on Python, we mentioned how Python is great for displaying fancy charts and graphs. The same is true of JavaScript. If you have a lot of data that you’d like to showcase, then JavaScript offers myriad ways of getting it across.

If you’d like to learn more about Data Visualisation in general, we’ve got courses geared at all levels, including Data Visualisation with Python: Matplotlib and Visual Analysis, and Data Visualisation with Python: Bokeh and Advanced Layouts.

How to program with JavaScript

We won’t delve into the nuts and bolts of JavaScript here. What we will do is give you an idea of how fast you can expect to progress, and what you can do to make it happen that much more quickly.

How long does it take to learn JavaScript?

Our Introduction to Web Development provides a great starting point for would-be website builders, and it uses Javascript extensively. You’ll be finished after three weeks, with around two hours of study per week. Of course, the more time you’re willing to commit, and the more often you’re committing it, the better your results will be.

It’s best to start walking before you run. Don’t worry about frameworks until you’re familiar with the underlying mechanics of how the language works. While frameworks, like MeteorJS, provide additional features and functions, they’re specialised and prone to frequently changing.

If you know the fundamentals, then you know how to use JavaScript — and you’ll continue to know it whatever changes are made to the frameworks.

Can I learn with a programming course?

It’s possible to teach yourself JavaScript. But you’ll get there faster with the help of expert instruction. Every amateur programmer can tell you a story of how they spent hours staring at a screen, trying to work out a solution to a problem that was quite straightforward in hindsight.

Guided learning will help you to avoid these problems, and make the process of learning the language that much more enjoyable.

If you already know a little bit and want to leverage the power of JavaScript frameworks, then you might look into this course on Using JavaScript, jQuery, and JSON in Django from the University of Michigan (Django being a Python web framework).

How long is a full-stack JavaScript course?

A full-stack developer is a person who can work with the back-end of a website as well as the front. This typically means mastering (or at least, dabbling in) a range of languages. Given that Javascript can cope with a whole range of applications, you might assume you could become a full stack developer without learning anything else. 

In practice, however, a competent full-stack developer is familiar with a range of different languages. That way, you’ll be able to bring the appropriate skills to all kinds of tasks. In this case, it’s best to look into courses that deal with web development as a whole, like Introduction to Web Development by Raspberry Pi Foundation.

 Final thoughts

You might think of JavaScript, and programming in general, as something arcane and intimidating. But provided that you start in the right place, and build your knowledge and skills via a series of small, logical steps, there’s no reason you can’t become a competent JavaScript developer. 

If you’d like to get started, you might check out our How to Become a JavaScript Developer career page, or, the Computer Programming for Everyone course from the University of Leeds.

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