Java vs JavaScript: What’s the Difference and Which Language Should You Learn?

Did you know that Java and JavaScript are not related at all? That’s right! Despite their similar names, they are two completely different programming languages that were initially designed for different purposes. If you are new to coding and want to build a successful career in tech, you might want to know how Java and JavaScript differ and where they are typically used. That knowledge will help you avoid mistakes and set you on the path toward a career that’s right for you.

“Java” in the name, are they the same?

Before we dive into the details of Java vs. JS, let’s take a brief look at their origin. 

Java was created by James Gosling at Sun Microsystems in 1991. Initially designed for interactive television, it failed to meet market expectations. However, Java found its niche in desktop apps and server-side programming — the background software that runs on a server, e.g. if a user logs in to an online banking website, it can use Java to verify the user’s identity and communicate with a server that stores the user’s account information and transaction data. It was officially released in 1996 with the slogan: “Write once, run anywhere.” This means that Java code can run on any device that supports a Java Virtual Machine (JVM — more on that later). You can have a look at how Java works in our article.

JS, on the other hand, was created by Brendan Eich at Netscape in 1995. The initial version was built in just 10 days and was originally called Mocha, then LiveScript, and, finally, JavaScript. Basically, Netscape management just wanted to capitalize on some Java hype, so, it’s the only reason both languages have "Java" in their names. 

JS was designed as a language for web browsers, to add interactivity and dynamic features to static web pages. For example, JS can be used to create a slideshow of images that changes automatically or when the user clicks on a button. Another way to use it would be to animate elements on the web page, such as fading, sliding, or zooming. JS was first used with the Netscape Navigator 2.0 browser in December 1995. So, JS started as a language for web development.

Summing up, Java and JS are not related at all, aside from the fact that they are both popular programming languages with suspiciously similar names. In fact, Java and JS are like donuts and Doritos. Both are snacks and both start with “do”, but they are not even in the same snack category.

Comparison of Java and JS under the hood

Java is a compiled language, meaning that it needs another program to “translate” its code into something that your device can understand. This program is called a compiler and it makes a special kind of code that can work on any device. But this code still needs another program to run it. This program is called a Java Virtual Machine (JVM) and it acts like a mini device inside your device. This makes Java portable: any device with a JVM can run this language.

Java is also a statically typed language, meaning that when you make things with code you have to be specific about the type of thing you are making. For example, if you use words, you have to say they are words. And once you say they are words, you can’t change them to numbers or something else. This makes Java more careful, less flexible, and more demanding in terms of learning than other languages.

JS is a language that doesn’t need a separate compilation step. It can run its code as it is in any browser. JS is also a language that doesn’t need you to tell it what kind of information you are using. You can use any kind of data and change it whenever you want. This makes JS more free and flexible.

Moreover, JS is much more forgiving than Java in the early stage of building an app, and it is easier to learn. Still, Java’s lack of forgiveness means it’s less prone to errors (or bugs) in the long run compared to JS. In other words, Java apps take more time to get off the ground. But, once you’ve set the structure up, maintaining it is much easier compared to a JS app. At the same time, launching a JS app is relatively easy, but the upkeep effort increases over time. To put it concisely, coding in Java is a slow start, but promises stability; while JS is quick to pick up, but hard to maintain.

Now that we’ve covered the history and tech details, let’s check out where both languages are applied.

Comparison of Java and JS use cases

Java is one of the most frequently studied programming languages in the world. It is widely used for creating desktop and mobile apps and server-side programming.

Some of the typical use cases for Java are:

• Desktop apps: Java can create graphical user interfaces and standalone apps that run on any device with a JVM. An example is Acrobat Reader, which uses some Java components for its functionality, such as the iText library that creates and manipulates PDF documents.
• Mobile apps: Java is very popular for developing Android apps. A great example is Spotify, which allows you to stream music, podcasts, and playlists.
• Server-side programming: For example, Google is a web service that uses Java for some parts of its search engine.
• Games: Java can create 2D and 3D games that run on any device with a JVM. An example is the video game Minecraft, which lets you create and explore virtual worlds made of blocks. It is written in Java and can run on Windows, Linux, and Mac OS X.
• Hardware: Java powers the Internet of Things. For example, Airbiquity uses it to remotely update connected cars’ software and firmware over the air.

JS is a language that is mainly used for creating interactive websites and web apps, but it has also found other use cases nowadays. Some of the examples are:

• Web development: JS can create dynamic and interactive websites and web apps. For example, Gmail uses JS to allow users to send and receive emails, manage their contacts, organize their inboxes, etc. It also uses JS to update the content of the web page without reloading it, making it faster and more responsive.
• Front-end development: JS can create user interfaces (UIs) and user interactions (UX) for web apps. For example, Facebook applies JS to create a UI that shows people their news feeds, friends list, notifications, messages, etc. It also uses JS to create UX features such as reactions, comments, likes, shares, etc.
• Back-end development: JS can also create back-end systems for web apps. For example, PayPal uses JS to handle payment transactions, user verification, currency conversion, etc. It also uses JS to create a UI that shows users their balance, activity, wallet, etc.
• Mobile development: JS can create cross-platform mobile apps. For example, Instagram is a mobile app that uses JS to show users their feeds, stories, explore tabs, etc. It also uses JS to create UX features such as filters, stickers, direct messages, etc.
• Data visualization: JS can create charts, graphs, maps, and other visual representations of data. For example, Google Maps uses JS to create UX features such as zooming, panning, searching, etc.

Summing up, Java is not commonly used in web development. Its realm is more away from the web, e.g. in hardware and Android apps. Many massive industries require a stable language like Java, such as banking, the automotive industry, trading, etc. It’s also used for scientific computing and general-purpose hardware programming, like the Internet of Things.

So, if you want to specialize in mobile app development or create apps that run on any device, choose Java.

On the other hand, JS dominates the world of web development nowadays. Unlike Java, it was originally reserved for the front end of a website ― the part that humans interact with, using a mouse or a trackpad, etc. Still, developers have spent years creating massive coding libraries that can extend the capabilities of JS outside its usual web browser box. And that’s what modern companies like Facebook, Twitter, and Airbnb use to power their businesses and technologies. 

So, if you want to specialize in web development or create dynamic and interactive websites and web apps that run on any browser, choose JS.

Salaries for Java and JS developers

The average salary of a Java and JS coder varies depending on the location, experience level, and industry.

Still, we can say that Java generally pays more: it is a more mature and widely used language that requires more complex skills and knowledge. It is in big demand in “old”, established industries such as banking, automotive, trading, and so on. But it doesn’t mean things can’t change: modern companies like Uber, Facebook, and Netflix are pushing strongly toward JS-based technologies.

To illustrate the above, here are some numbers from Glassdoor on the annual average salary of developers per state:

How to become a Java or JS developer

Becoming a Java or JS developer can be a rewarding career choice for anyone interested in programming and web development. There are different paths you can take to achieve this goal, but here are some common steps that can help you along the way:

• Learn the basics of programming: Before diving into Java or JS, it is important to understand the basics of programming logic and syntax. For example, check out V. Anton Spraul’s Think Like a Programmer: An Introduction to Creative Problem-Solving.
• Learn Java or JS: After gaining a solid foundation in programming, you can start learning the language itself.
• Build projects and portfolio: In order to gain practical experience and develop your skills, you should start building your own projects. You can begin with small tasks, such as a simple calculator or a to-do list, and gradually move on to more complex jobs. Building projects will help you apply the concepts you have learned and develop problem-solving skills. You should also create a portfolio of your projects to showcase your work to potential employers.
• Get involved in online communities and networks: Joining online communities, such as Stack Overflow, GitHub, and Reddit, can help you connect with other developers, ask questions, and get feedback on your projects.

There are different paths available to you in order to gain the above skills, from self-learning to getting a university degree. But if you want to learn Java or JS fast, you should consider joining a coding bootcamp.

For instance, our Software Engineering Bootcamp will give you a solid foundation in JS and the basics of working with the browser. You will learn from experienced instructors, work on real-world projects, and receive feedback and support from your peers and mentors. You will also gain access to career services, such as resume-building, interview preparation, and job placement assistance.

Two opportunities

Java and JavaScript are two distinct programming languages with different origins, purposes, and technical features. Java is commonly used for creating desktop and mobile apps, server-side programming, games, and hardware.

Meanwhile, JavaScript is widely used for web development and creating interactive and dynamic web pages. Java requires more effort in the early stages, but is more smooth to operate later, while JavaScript offers a fast start, but harder maintenance.

Here are the crucial things to know about both languages:

We hope that knowing the difference between these languages will help you choose the right path toward your new career in tech. And don’t forget: whatever language you learn first, you can always learn more later as you continue your journey.