Java vs. JavaScript: 4 Key Comparisons

Java is used for programming across domains, while JavaScript is used to create interactive web content.

November 3, 2022

Java is defined as an object-oriented, class-based, all-purpose programming language. On the other hand, JavaScript is defined as an object-oriented, cross-platform scripting language used for creating interactive web content. This article covers the four key comparisons between Java and JavaScript.

Java vs. JavaScript

While Java is an object-oriented, class-based, all-purpose programming language, JavaScript is an object-oriented, cross-platform scripting language for creating interactive web content.

What Is Java?

Java is an all-purpose, object-oriented programming language. It also serves as a platform, enabling Java code to be executed on any computer powered by a Java Virtual Machine (JVM).

Initially, both terms were interchangeable because Java was the only language that ran on JVM. However, that is no longer the case; new languages such as Groovy, Scala, JRuby (an implementation of Ruby), and Jython (an implementation of Python) are written for execution on the Java platform.

Sun Microsystems was the creator of Java, releasing it in 1995. Subsequently, the company was acquired by Oracle Corporation, making Oracle the official owner of the Java SE platform.

Interestingly, Java was initially envisioned as a programming language that would run on consumer appliances, a concept we now know as the internet of things (IoT). One of the key features of Java is ‘write once, run anywhere’, enabling programmers to write code that one can compile for execution on any device. However, this was not the original reason for Java’s popularity. Instead, it was the rise of the world wide web; another early Java feature was its usage for writing applets. These small programs could be executed inside web browsers, giving Java a unique functionality that led to its popularity for writing many web applications.

Today, Java is an excellent first language to learn for people trying their hand at programming. It has been in mainstream use for over two decades and is well-established, with numerous excellent resources for learning it. It is also perhaps the most used language among programmers, making it easier for newbies to find mentors.

Additionally, Java syntax is derived from C, like numerous other languages. As such, learning Java makes learning more accessible than other widely used languages such as JavaScript, C#, and C++. The fact that Java is an object-oriented language also means that its foundational concepts are transferable to other programming languages.

The Java language is open-source, as are many purpose-built Java tools, frameworks, and libraries. Developers can use many Java implementations for free, including OpenJDK, the open-source counterpart of Oracle’s proprietary Java Development Kit (JDK).

One everyday use of Java is in Android-powered smartphones; however, JVM is not used here. Instead, the source code is compiled explicitly for the Android runtime. While the Java code running on an Android smartphone may appear to be different from the code for a web application, it is the same source code.

Java’s ubiquitousness is apparent in that even tech giants such as Google and Amazon use it. It is better suited for creating large enterprise software solutions. While it can be (and is) used for smaller applications, it might be a little heavyweight for quick DevOps scripts.

See More: What Are Microservices? Definition, Examples, Architecture, and Best Practices for 2022

What Is JavaScript?

JavaScript is an object-oriented scripting language that offers cross-platform functionality and is primarily used for creating interactive web pages. A few everyday use cases for JavaScript include creating clickable buttons, complex animations, and pop-up menus.

Advanced server-side JavaScript versions like Node.js enable users to boost website functionality with features such as real-time collaboration. Inside web browsers and other host environments, JavaScript offers connectivity among objects, enabling users to exercise programmatic control over them.

Like Java, JavaScript’s origins lie in the early days of the world wide web. As the world increasingly gained internet access in the 1990s, technology pioneers raced to build a robust, efficient internet browser. Two major companies, Microsoft and Netscape, wanted to push out Internet Explorer and Netscape Navigator, intending to dominate the web browser market.

To win this ‘browser war’, Netscape was looking for a lightweight scripting language to make programming easier and remove the need for in-depth programming knowledge among employees. It was in 1995 that Brendan Eich, a Netscape team member, took on the challenge of building such a language within ten days. He created Mocha, the predecessor to JavaScript.

Once AOL acquired Netscape and the Mozilla Foundation gained access to Netscape Navigator’s source code, JavaScript grew in popularity. Today, this critical web technology is a key component of most popular web browsers. Web developers generally include JavaScript in their stack; the Stack Overflow Developer Survey constantly pegs JavaScript as one of the most commonly used languages among programmers.

How exactly is JavaScript related to Java? While both are popular programming languages with a host of commonalities, the reason for the similarity in their names is nothing more than simple marketing. The main reason Mocha’s name was changed to JavaScript was to gain from the exploding popularity of Java at its peak.

But be it for this reason or due to its robust functionality, this scripting language put together by one person in just 10 days has today become a favorite of the world wide web. JavaScript’s success also stemmed from the fact that it transformed web browsers into application platforms. It did so through its useability in both back-end and front-end web development.

Other advantages of JavaScript include the fact that it is standardized, allowing for frequent updates and its compatibility with the document object model (DOM) for responding to user interactions. It is still the preferred tool for giving websites interactivity functions such as object movement and scroll transitions. Modern browsers still strive to enhance the user experience by processing JavaScript as swiftly as possible.

Additionally, JavaScript users can access numerous libraries and frameworks for developing complex applications without heavy resource use. Importing these frameworks and libraries into code allows programmers to bolster their applications.

Apart from offering numerous possibilities to programmers, JavaScript is the only browser-native programming language and has a low barrier to entry. This, combined with the other reasons we’ll discuss below, make it one of the world’s favorite scripting languages.

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JavaScript vs. Java: 4 Key Comparisons

Now that we are familiar with the fundamentals of Java and JavaScript, let’s take a look at the four key comparisons between them.

1. Key Features

Java JavaScript
Object-oriented: Java’s flexibility and reusability are enhanced due to being an object-oriented programming language. One can reuse its objects easily in other programs. Additionally, users can bind data and functions into a single, selectively accessible unit to increase security. Bigger modules can also be organized into smaller ones, making them easier to understand.

Simple: Java is easy to learn and understand. Its syntax is straightforward and hassle-free to write and maintain. Debugging the code is simple too. Apart from this, complex features of C and C++, such as explicit pointers, operator overloading, and storage classes, are not present in Java.

Platform-agnostic: Java programs are simple to develop and maintain across platforms. Code is written only once and then adapted to specific machines as required, regardless of the operating system, as long as Java Virtual Machine (JVM) support is present. This also makes it portable among platforms.

Secure: No explicit pointers reduce the security risks in Java. Each Java application has a security manager that enables users to define class access rules.

Automated memory management: This is one of the key features of JVM, allowing it to remove unused objects using the ‘automatic garbage collection’ process. This includes objects that are not used by programs or do not refer to anything.

High-level, stable, distributed: Java is human-readable and uses a simple syntax. Regular updates keep the language stable while providing a data-sharing mechanism across multiple computers. Java’s distributed capabilities are supported by remote method invocation (RMI), socket programming, and CORBA technology.

Efficient memory allocation: Java divides memory into two main parts–stack area and heap area. The memory space for any variable is provided by JVM from one of these areas.

Multithreading support: As a multithreaded language, Java allows multiple threads to run independently at once, thus maximizing CPU utilization and application performance.

Easy to use: Users can learn and understand JavaScript easily, and its structure is simple for use by developers. Its high implementation feasibility helps develop dynamic web content swiftly. All this is further simplified with third-party add-ons that enable developers to add predefined code segments in their code to make development even easier.

Speedy: As a language, JavaScript is ‘interpreted’, meaning it takes less time than Java for compilation. Apart from this, it is a client-side script, allowing for faster program execution.

Lightweight: JavaScript boosts application performance by reducing code length. Code overhead is minimized through built-in functionality for loops, DOM access, and other aspects.

High interoperability: JavaScript is highly compatible with other programming languages, making it a popular choice for application development. For instance, users can easily embed it into a web page or another programming language’s script.

Makes interfaces rich: Various JavaScript interfaces allow developers to create rich web pages with features such as drag-and-drop or sliders. This enhances user interactivity and overall experience.

Decentralized: Client-side operations are a key feature of JavaScript, bringing data validation to the browser rather than relying on the server. Only the selected web page segment can be reloaded if a discrepancy is spotted.

Versatile: JavaScript is used for front-end (ReactJS, AngularJS, etc.) and back-end (NodeJS) development.

 

2. Operations

Java JavaScript
Java is a strongly typed language that requires variables to be declared before being used in a program. The variable type is checked during compilation.

Java is a standalone language that is more oriented toward programming. One can execute it in any instance of JVM or browser. Java objects are class-based, and one cannot make Java programs without creating a class. Its file extension is .java.

In Java, source code is translated into bytecodes that are then executed by JVM. The language supports multithreading and takes a thread-based approach to concurrency.

Java is more memory-intensive than JavaScript and is primarily used for back-end applications. It needs a Java development kit (JDK) for code execution.

JavaScript is a loosely typed language that is not as strict as Java when it comes to rules and syntax. It is more oriented toward scripting.

Originally, JavaScript code could only be executed inside a web browser. However, NodeJS can now be used to run it on servers. JavaScript objects are prototype-based and it uses the .js file extension.

JavaScript is interpreted but not compiled, as browsers normally use JavaScript interpreters to run JS code. The language does not offer multithreading support and takes an event-based approach to concurrency.

Compared to Java, JavaScript is less memory-intensive and leveraged for front-end and back-end applications. It requires a browser console or text editor for code execution.

 

3. Applications

Java JavaScript
Thousands of companies worldwide use Java to bolster their tech stacks.

A June 2022 article by CodeGym pegs Java clients’ market share in the US at over 60% (approximately 64,000 businesses).

Here’s a list of the top companies that leverage Java in their day-to-day applications:

Microsoft

The Microsoft Edge browser is powered by Java. Apart from this, the software giant has a strong interest in the programming language, investing in its development to promote industry-wide advancements. A statement from the Microsoft website states, “Java at Microsoft spans from Azure to Minecraft, across SQL Server to Visual Studio Code […] and beyond! We use more Java than one can imagine.”

Uber

Known for dealing with tremendously high volumes of real-time data, Uber uses Java to handle requests and transfer data swiftly. The language helps the ride-hailing pioneer track its drivers and manage ride requests, allowing seamless data sorting and user matching.

LinkedIn

Numerous parts of this social media for professionals are written using Java, with certain elements made with C++. Among other aspects, Java is key in LinkedIn’s search and analytics functions. It also helps resolve scale issues, allowing the server to operate swiftly while using fewer resources.

NASA WorldWind

Java is the base of NASA’s immersive WorldWind application. This hyper-realistic virtual globe displays precise geographical information by using real images captured by satellites to create a 3D model of the planet.

And many more!

Apart from the tech giants mentioned above, Java is used by Netflix, Airbnb, PayPal, Google, Spotify, eBay, TripAdvisor, Pinterest, Intel, Slack, Groupon, Flipkart, and many other companies.

Just like Java, JavaScript is integral to many leading tech companies. These top companies use the popular scripting language:

Facebook

A lot of JavaScript goes into keeping Facebook up and running. For instance, different sections of Facebook load separately because the company has created a unique methodology for breaking down and loading JavaScript sections independently. 

Simply put, each section of a Facebook page is a collection of separate JavaScript applications. Additionally, Facebook is the developer of React, a well-known front-end framework that is used on Facebook, WhatsApp, and Instagram.

Google

From the results that appear when a user types into the search bar to Gmail and even Google Docs, JavaScript powers huge chunks of Google’s applications.

Google is also renowned for developing and often releasing the open-source code of its JavaScript solutions. 

A well-known example is AngularJS, a prominent part of Google’s DoubleClick ad platform and a popular front-end framework. 

Additionally, Google Chrome is the reason for the existence of the V8 JavaScript engine, which is also the base for NodeJS.

Microsoft

JavaScript, like Java, is integral to the Edge web browser. Microsoft has developed an in-house JavaScript engine for Edge.

Besides, Microsoft has adopted NodeJS and supports it on Azure Cloud, which has integrated Visual Studio compatibility for Node. Finally, Microsoft developed a version of Node for IoT applications. 

Netflix

In the beginning, Netflix relied on Java for most of its functionality. However, Java’s size and development time led to challenges, driving the streaming giant to move to the cloud and adopt NodeJS.

Node enables Netflix to break down its user interface into separate services. This distributed methodology enabled the company to minimize server load and boost service speed.

PayPal

The front-end of the PayPal website relies on JavaScript. However, that’s not all; the online finance leader is one of the earliest users of NodeJS.

Like Netflix (and for similar reasons), PayPal overhauled its account overview page and adopted Node along with its normal Java development. This was a success, leading PayPal to use Node to create all client-facing applications.

Today, most sections of a PayPal user’s account run on Node, and the company has even created KrakenJS, its version of Express (the de facto standard server framework for Node).

 

4. Careers

Java JavaScript
Java experts can make a lucrative career for themselves in any of the following domains:

Web development

Java is used for the back-end development of web applications and server-side applications. Web developers must be skilled in HTML and CSS, as well as have knowledge of APIs. Building a Java web application also needs the know-how of dynamic resources, including servlets, JavaServer Pages, and Jars.

Mobile app development

Numerous widely-used mobile applications, including Spotify and Twitter, are developed using Java. A Java developer should be well-versed in Android Studio, emulators such as vMac and Dolphin, and user interface (UI) design. Good-to-have skills include XML and application programming interfaces (APIs).

Enterprise applications

Enterprise applications for organizing and modeling business processes are developed using Java Platform, Enterprise Edition (Java EE).

Gaming

Java developers have exciting career opportunities in gaming. The language is used to create cross-platform game versions without extra development costs. Java is also popular for creating 2D Android games. Developers must be familiar with gaming physics, multithreaded Java applications, and garbage collection.

Desktop GUI

Java is also used for desktop application development. These developers must be skilled in making widgets using tools like the Swing GUI toolkit. The abstract window toolkit (AWT) in the Java development kit (JDK) is used for creating cross-platform applications. Standard widget toolkit (SWT), IBM’s programming library, is also used for building desktop applications. SWT, combined with Eclipse RCP, is gaining prominence in this domain.

Science

Java is popular for developing applications capable of executing multiple scientific calculations and mathematical operations, particularly due to its swift processing speed. Knowledge of Java with the CUDA toolkit is helpful here.

Those well-versed in JavaScript can ace the below-listed job roles:

DevOps engineer

This role is responsible for server software, deployment, version control, testing servers & processes, build processes, and other functions. They undertake numerous critical duties, including deployment of updates, addressing technical issues, creating tools to minimize errors, enhancing user experience, and coordinating with the back-end.

JavaScript development

JavaScript developers link developed elements with the back end. They are responsible for programming, developing applications and liaisoning with front-end and back-end developers.

Web application development

Web-based software applications include ecommerce shopping carts, interactive online forms, spreadsheet programs, word processors, photo & video editors, email clients, file converters, and scanning programs. Developers must be adept at tools such as Adobe AIR, ELECTRON, and jQuery.

Full stack development

These developers are capable of working on the front end as well as the back end.

They design the entire web application architecture and work with engineers on establishing features and are familiar with cybersecurity as well. Skills include Ruby, Python, PHP, Java, and .NET.

Front-end web development

These developers build the visual, user-facing aspect of websites. They must be skilled in HTML, CSS, and the basics of back-end development. Regression testing is a bonus skill here.

UI/UX designing

These professionals are responsible for designing applications and researching how people use them. Must-have skills include UI design tools, HTML, CSS, interface designing, and user experience designing.

See More: What is Root-Cause Analysis? Working, Templates, and Examples

Takeaway

Despite their similar-sounding names, JavaScript and Java are not part of the same platform. While Java is an object-oriented programming language, JavaScript is an object-oriented scripting language.

The former is used for creating applications that one can execute in a browser or virtual machine. In contrast, the latter can be executed only on a browser (or a server when using specific implementations). They require different plug-ins, and while one must compile Java code, JavaScript code is all in text. These two languages also share differences in terms of key features, operations, applications, and career paths.

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Hossein Ashtari
Interested in cutting-edge tech from a young age, Hossein is passionate about staying up to date on the latest technologies in the market and writes about them regularly. He has worked with leaders in the cloud and IT domains, including Amazon—creating and analyzing content, and even helping set up and run tech content properties from scratch. When he’s not working, you’re likely to find him reading or gaming!
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