Java vs JavaScript: Know The 8 Major Differences

When you hear the terms Java and JavaScript, it’s likely that you get confused between the two and might even use them interchangeably. However, they are different. In this article on Java vs. JavaScript, we’ll discuss these crucial differences.

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What is Java?

Developed by James Gosling and his team, Java is the most commonly learned and used programming language globally. It is a cross-platform, object-oriented programming language that is primarily used to develop applications and for database management. It overcomes the drawbacks of C and C++ and provides better memory management and security. More than 3 billion mobile phones are built using this language since it is used to develop android applications, servlets, struts, or JSPs. With over 1 million repositories on Github, it’s no surprise that Java has a vast and active community of developers.

Now let’s understand what exactly JavaScript is.

What is JavaScript?

Developed by Brendon Eich in 1995, JavaScript is a server-side and client-side programming language. It is commonly used to create web applications. Users with the knowledge of JavaScript can play with any layer of the application. Some of the key features of this language are: 

  • Incredible speed
  • Cross-Platform Compatibility
  • Ease of use

It is used in conjunction with other languages like Perl and PHP and markup languages like HTML and CSS to create a web application from scratch. Applications of JavaScript can be seen in diverse fields like gaming, web development, server development, and robotics, among others. 

Popular JavaScript libraries and frameworks like ReactJS and Angular have scaled tremendously in the past few years. Companies like PayPal, Netflix, Facebook, Google, Uber, and HBO use JavaScript and their frameworks in their products.

Now that you know what Java and JavaScript are, in the following section, let’s compare the two languages. 

Java vs. JavaScript

Both Java and JavaScript play a significant role in the IT industry. In the following section, we will compare the two languages to understand them better. 

1. Object-Oriented Programming

Object Oriented Programming

Java and JavaScript are both object-oriented programming languages. Concepts like Encapsulation, Inheritance, Polymorphism, and Abstraction are readily used by the two. Both languages use objects and classes to perform actions. However, the only difference is that Java is a programming language, while JavaScript is a scripting language. 

2. Syntax

Java uses syntax that is similar to C or C++. JavaScript uses a syntax similar to the C programming language. Since both the languages use objects and classes, the syntax remains quite similar. 

3. Variable Definition 

Java is a statically typed language. All the variables in the program need to be declared before they are initialized or deployed. JavaScript, on the other hand, is a dynamically typed language. A variable declaration can be made as and when they are used. 

4. Compilation 

Java is both compiled and interpreted. Every Java program is first compiled to byte code, which the Java Runtime Environment (JRE) understands. These byte codes are then interpreted by the Java Virtual Machine(JVM), making it an interpreted language. On the other hand, JavaScript is a strictly interpreted language. In this case, every instruction in the program is interpreted line by line and checked for bugs.

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5. Running Platform 

Java programs and applications run on the Java Virtual Machine (JVM). This is typically installed when the Java Software Development Kit (SDK) is installed. JVM provides the platform for executing the Java code. It interprets the byte code during execution. 

JavaScript programs run on the web browser. They do not require any initial setup.

6. Concurrency 

Java uses a thread-based approach. This approach divides the program into tiny pieces of code in the hardware that are run concurrently. This makes it fast and requires lesser overhead. JavaScript, on the other hand, uses an event-based approach. Event-based applications divide work up using callbacks, an event loop, and a queue. 

7. Compatibility

Since both these languages are so widely used, there’s no doubt that they offer excellent compatibility. Java is cross-platform compatible and supports Operating Systems like Windows, macOS, and Linux. JavaScript is also cross-browser compatible and supports browsers like Chrome, Firefox, and Safari, among others. It also supports different operating systems.

8. Salary 

The average salary of a Java developer in the US is around 74,000 USD per annum. The average salary of a Java developer in India is approximately 4,50,000 INR per annum. 

The average salary of a JavaScript in the US is around 82,000 USD per annum, and the same in India is around 3,40,000 INR per annum. 




Programming Paradigm

Object-oriented programming language

Scripting language with multiple paradigms




Type checking 

Statically Typed

Dynamically typed


Compiled and interpreted

Strictly interpreted 

Running platform

Runs on the Java Virtual Machine

Runs on a web browser


Thread-based approach

Event-based approach


Supports multithreading 

Does not support multithreading

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Next Steps 

We hope that this article on Java vs. JavaScript helped you understand the differences and similarities between the two languages. If you wish to learn these programming languages and perhaps make a career as a developer, then a course certification will come in handy.

Simplilearn's Java Certification Training Course is designed to guide you through the concepts of Java from introductory techniques to advanced programming skills. This course will also help you with concepts like Core Java 8, operators, arrays, loops, methods, and constructors while giving you hands-on experience in JDBC and JUnit framework.

You can also check out our Full Stack Web Developer - MEAN Stack Master’s program to learn top skills such as MongoDB, Express.js, Angular, and Node.js (“MEAN”), plus GIT, HTML, CSS, and JavaScript.

If you have feedback or questions, drop us a comment in the comments section. Our experts will get back to you ASAP! 

About the Author

Chinmayee DeshpandeChinmayee Deshpande

Chinmayee is a Research Analyst and a passionate writer. Being a technology enthusiast, her thorough knowledge about the subject helps her develop structured content and deliver accordingly.

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