Java vs JavaScript: what are the differences?

What is Java vs JavaScript?

Want to write a program and be able to run it basically anywhere? Use Java. Want to make your webpage interactive? You want JavaScript.

While Java is a long-time mainstay of the programming community – especially among corporations who want to either write code that will be useful in the long-term or keep using code that was written decades ago – JavaScript is a young whippersnapper.

While interest in JavaScript has increased overtime, the relative importance of Java has slightly declined.

As the above chart from Google Trends shows, JavaScript has significantly increased in search intent popularity relative to Java. This chart is easy to misinterpret – it doesn’t show monthly searches for each term. It charts the difference in popularity between the two terms.

Why has JavaScript – or simply ‘JS’ – increased in popularity so much relative to Java? That Google Trends chart goes all the way back to New Year’s Day 2004. Do you remember the internet back in 2004?

If you’re too young to remember – congratulations, by the way – the internet was substantially less interactive than it is today. If you’re picturing a lot of painfully static pages, that’s not far from a representative picture of what browsing was like back then.

Why? Less JavaScript.

JS is now the Atlas holding up the massive weight that is engaging and interactive web content. Want to use a map on a website? Or play around with a 3D model? Or play an embedded file of some kind? You have JavaScript to thank.

JavaScript is the exciting fireworks display of web development.

Java, on the other hand, is the highly successful uncle who sensibly drives a sensible Volvo to his sensible corporate office.

But if you’re thinking that means Java isn’t used by some very exciting organisations, you’d be dead wrong.

Uber was built with Java. Twitter’s interface? Also Java. Minecraft? Java. Java can do a lot of different things. So, while AirBnB uses Java in its backend development – as does Spotify, by the way – one of the most popular video games of the last decade is also running on Java.

So, there is some overlap between the two. You can find both Java and JavaScript floating around as you browse the internet.

We’ll get into more specifics about how Java and JavaScript can be used later, but here are some other important differences:

• Java is an object-oriented programming language. More on that later. On the other hand, JS is technically a scripting language. That means it’s used to automate the ‘execution’ (or, doing) of tasks so that the code follows a script, if you like!
• Java runs programs in a ‘virtual machine.’ You can think of a virtual machine as a piece of software pretending to be a computer inside an actual computer. That’s why Java-built programs are so portable. The virtual machines they can run in are always compatible with them, and you can move the virtual machines to new places. Of course, Java’s flexibility also lets it run in a browser, like JS.
• Java is static. JavaScript is much more dynamic.
• The file extension for JavaScript is .JS. The file extension for Java is .Java.

Next up, that info on object-oriented programming (or OOP) we promised earlier.

What is object-oriented programming? (OOP)

Object-oriented programming (or OOP) is an approach to programming found in many popular programming languages. OOP is distinctive for focusing on ‘objects’ instead of functions or logic.

To simplify, in OOP developers focus on the things that are being manipulated rather than the process of manipulation itself.

OOP is good for large or complex programs because placing the focus on the object allows for a more intuitive development process with greater clarity of responsibilities. As you might expect, this plus the modularity contributes greatly to the popularity of OOP programming languages like Java among organisations with large, complex datasets or needs.

What is Java used for?

Short answer; a lot. While Java is most popular for backend development projects on the server-side, it’s frequently used in a range of other areas, including:

• Big data management and analysis
• Mobile app development, especially for Android
• Desktop development projects
• Game development

With such versatility, it’s no accident that even after more than a quarter of a century, Java is still the third most popular programming language around.

What is JavaScript used for?

JavaScript (JS) is the preeminent programming language for interactive web applications and web content. If you want content that changes without the need to refresh the page, JS is the way to go.

As a result, much of the modern internet simply wouldn’t be possible without JavaScript. That’s why it’s one of the key pillars of Jamstack – a dynamic approach to web development that’s growing in popularity.

Ready to learn more?

Let’s say you want to learn about programming and software development. There’s a lot to discover. Even if you’re learning to code, it’s not enough to complete some courses in the most common programming languages.

There’s a whole world of terminology, history, business skills, and important background to discover. If you found this article on the differences between Java and JavaScript helpful, you’re at the stage in your learning journey where a few well-written, high-level overviews of the tech space can give you a powerful leg up.

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