Career Insight

Java vs Javascript: What’s the Difference?

Java vs Javascript: What’s the Difference?

What sounds like a heavyweight fight for the ages, Java vs Javascript is anything but. While they both play an integral role in the IT industry, there are several differences between these languages, including their function, purpose, and, of course, spelling.

On the surface, you might assume “Java” and “Javascript” are closely related. In this instance, that isn’t the case. Rather than having a sibling-like relationship, consider the two more as very distant cousins.

Here’s what you’ll learn:

  • What is Java?
  • What is Javascript?
  • How Are They Similar?
  • How Are They Different?
  • Why Java?
  • Why Javascript?
  • Parting Thoughts…

Now, let’s dive in.

What is Java?

Java is an object-oriented programming language and software platform. It began as an idea in 1991 when Sun Microsystems and their lead developer, James Gosling, broke ground on what they believed would be a game changer in the world of IT. After four years of development, the first fully functional Java technology launched in 1995, changing the World Wide Web forever.

Twenty-six years later, Java is still ingrained in everything IT-related. It runs on everything, from laptops, data centers, and TVs to game consoles, mobiles, and scientific supercomputers. As of today, Java is the #1 language for DevOps, AI, VR, big data, continuous integration, analytics, mobile, chatbots, and social. From the beginning, Java paved the way for the internet we know today.

What is Javascript?

Javascript (JS) is an object-oriented scripting language that allows developers to implement complex features on web browsers and applications. It was created amidst the web browser war between Microsoft and Netscape by Netscape programmer, Brandon Eich. While it took four years for developers to create Java, Eich was able to pull off the development of Javascript in only 10 days in September 1995.

Since its inception, Javascript has been an essential component of web development technology along with HTML and CSS. As CSS and HTML provide a website’s structure and style, JavaScript provides the ability to add interactive features and behaviors. Using Javascript, web developers can create a website with endless ways for website visitors to interact with content. As of 2021, more than 13.8 software developers worldwide claim to use Javascript.

How Are They Similar?

Java and Javascript both reside in the realm of IT. So let’s talk about it.

Syntax Similarities

In terms of syntax, Java and Javascript belong to the curly brace language family, in which you place your code inside a curly braced block. Statements are terminated with semicolons in both languages. In addition, some statements, expressions, and logical flow are the same between the two languages, such as while loops, for loops, if/else if/else statements, etc.

Browser Compatibility

In the modern web, JavaScript is ubiquitous across all web applications. Even PHP, Ruby, or JSP sites use fragments of JavaScript to make their pages work. Java in the browser has largely been deprecated by modern companies, and Java is primarily only seen in back-end server applications and the cloud.

Both Java and Javascript can run in a browser. Almost all modern browsers support Javascript, making it the preferred choice for developing websites. However, Java-driven Java applets are capable of running in browsers, too. The drawback with Java Applets is they can compromise compatibility and security, making them the less desirable choice.

Server Compatibility

Both Java and Javascript are capable of being utilized on servers. Java is known to be a powerhouse for web application servers such as JBoss, Apache Tomcat, and WebSphere. To support Javascript servers, Node.js has become popular and provides the appropriate environment for development.

Support For Object-Oriented Programming (OOP)

Java and Javascript are both multi-paradigm languages, which means they support more than one programming style. Both Java and JavaScript support object-oriented programming.

How Are They Different?

It’s finally time to answer the question, “How are Java and Javascript different?”


On one hand, Java is primarily used for all server-side development. On the other hand, Javascript focuses on writing client-side scripts for tasks such as JS validation and interactivity.

Compiled vs Interpreted

Java is a compiled language, which means the source code must be compiled on the server before the program can be distributed to the end-user. As an interpreted scripted language, Javascript involves using an interpreter that can handle source code right at runtime, which typically results in fewer coding restrictions.

Static Typing vs Dynamic Typing

Static typing is present in Java, whereas dynamic typing is present in Javascript. In statically typed languages, variables must first be declared as datatypes before they can be used. Conversely, dynamically typed languages allow variables to be created and initialized without specifying their datatype.

Strongly Typed vs Weakly Typed

Java is a strongly typed language while Javascript is a weakly typed language. With strong-typed language, type conversions must be handled explicitly by the developer. Weak-typing lets programmers use different types of values without using explicit typecasting.

Class-Based vs Prototype-Based

Java is a class-based programming language, which means that all properties, methods, and fields are defined by classes. However, Javascript uses a template to define its initial set of properties. Objects in Javascript can be assigned additional properties even after creation. 

Multi-Threaded vs Single-Threaded

With Java being multi-threaded, it can have different parts of an application that can run synchronously to handle different tasks. Though Javascript is single-threaded, it can call functions asynchronously, which creates a loophole for concurrency to occur with JS.

File Extension

Java programs have the file extension “.Java” while Javascript uses the file extension “.js”.

Why Java?

Developers can enjoy these benefits when generating programs using Java language, including:

  • The JVM (Java Virtual Machine) allows Java to run on any platform
  • A large pool of skilled developers are available
  • Wide selection of 3rd party libraries
  • Easy to learn, use, write, debug, and maintain
  • Supports functions written in other languages such as C and C++
  • Creates standard programs and reusable code
  • Offers a secure environment to mitigate potential risk
  • Excellent performance

Java is still a mainstay in modern programming. Here are some high-profile organizations that continue to use it:

  • Airbnb
  • Uber
  • Slack
  • Netflix
  • Spotify
  • Instagram
  • Google
  • Pinterest
  • Amazon

Why Javascript?

Here are a few reasons why Javascript is popular and well-respected in the IT community:

  • Perfect for client-side scripting
  • Platform independent, meaning it works everywhere
  • Easy to test, revise, debug, and maintain
  • Operates fast as it’s executed in the browser
  • Works with other programming languages
  • Extends for writing large apps
  • Immediate feedback to the visitors

Nearly every company uses Javascript to some degree on the front-end of their web applications, and Java cannot replace Javascript on the front-end. Javascript is also well-supported in the tech community as some of the largest companies use it in their back-end applications, including:

  • Walmart
  • LinkedIn
  • PayPal
  • Netflix
  • Groupon
  • Uber
  • Facebook
  • Google
  • eBay

Parting Thoughts…

What different career paths are available to a JavaScript or Java developer? If you learn JavaScript, you can move toward front-end applications, UX/UI, or companies that use Node.js. If you learn Java then your career can move toward Cloud engineering, big data, and back-end engineering positions.

Now that you’re an expert in the difference between Java and Javascript, does the prospect of learning more about the programming community’s two favorite languages excite you? Are you eager to find out what it takes to find a career in java programming and software engineering?

Related Reading

  • Date
    October 21, 2021
  • Posted In
    Career Insight
  • Share