Difference between Java and JavaScript | Java vs Javascript

Difference between Java and JavaScript | Java vs Javascript

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Updated on May 2, 2024 17:36 IST

The most important differences between Java and JavaScript lie in their use and execution. Java is a statically typed language. It is primarily used for backend development of various applications. On the other hand, JavaScript is a dynamically typed language which is mainly used for creating interactive frontend elements within web pages. However, using Node.js JavaScript can also be used for backend development.

Java and JavaScript are the most popular programming languages in the development industry. If you searched for this topic and landed on this article - most probably you are starting or planning to start your journey in the world of programming and yes just like you alot of people think java and javascript are related as they both have ‘Java’ in their names. But the fact is that they are very different and are NOT related to each other at all. One is used for mobile app development and the later for interactive webpage elements. In this article, we will understand the difference between Java and JavaScript. 

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Must Check: Free JavaScript Online Courses and Certifications

Table of Content

Difference Between Java and JavaScript

Below are the main differences between Java and JavaScript based on the feature of comparison: 

Feature Java JavaScript
Type Statically typed Dynamically typed
Execution Compiled to bytecode that runs on the Java Virtual Machine Interpreted or JIT-compiled, typically in a browser
Use Case Large systems like enterprise software and Android apps Interactive websites and lightweight server-side applications
Syntax Strict, with mandatory type declarations More flexible, with optional type declarations
Concurrency Uses threads and traditional concurrency models Employs event-driven, non-blocking I/O models
File Extension Typically uses .java  for source files.

Uses .js for source files.

Difference Between Java and Javascript with Examples

Let's understand it clearly with examples for each feature of comparison:

Feature Java Example JavaScript Example
Type A variable must be declared with a type: int num = 5; A variable can be declared without a type: var num = 5
Execution Java programs are compiled into bytecode which is platform-independent and runs on any device with a JVM. JavaScript code can be run directly in any modern web browser without prior compilation.
Use Case Java is used in developing Android applications like the Uber app. JavaScript is used for interactive features on websites like Facebook.
Syntax Java requires every variable to be explicitly typed and every exception to be handled or declared. JavaScript allows for much more flexibility in coding style and error handling, supporting on-the-fly type changes.
Concurrency Java's multithreading is used in high-concurrency applications like stock trading platforms. JavaScript's non-blocking I/O is used in real-time web applications like chat apps.

What is Java?

  • Java is a programming language introduced in 1995 by Sun Microsystems (now Oracle).
  • Created by James Gosling and team, including Patrick Naughton and Mike Sheridan.
  • Object-oriented and statically typed, derived syntax from C and C++.
  • Requires explicit declaration of variable types.
  • Programs are compiled into bytecode and interpreted by the Java Virtual Machine (JVM).
  • Bytecode can run on any device with a JVM, making Java platform-independent.
  • Class-based language, using classes as blueprints for creating objects.
  • Supports key object-oriented concepts like inheritance, encapsulation, and abstraction.
  • Widely used for developing desktop, web, and mobile applications.
  • Known for performanceJava-based, security, and reliability.
  • Java based applications can run on various platforms, including Windows, Linux, and Mac.


Aspect Description
What is Java?
A general-purpose, object-oriented programming language
Where is Java used?
Widely used for building various applications - web, enterprise, mobile, desktop
Why is Java important?
Popular language due to its versatility, robustness, and large developer community
How does Java work?
Compiled language - code is translated into machine code before execution
Is Java hard to learn?
Considered moderately challenging, with a steeper learning curve compared to scripting languages
What are some benefits of using Java?
Offers strong object-oriented features, platform independence (with Java Virtual Machine), and mature development tools


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Features of Java

Feature Description Example
Widely-used programming language Java is commonly employed in web development, mobile app development (particularly for Android), and enterprise software. You might use Java to create the backend for an online store or to build a mobile app for tracking fitness goals on Android.
Object-oriented Java focuses on creating objects that contain both data and methods to manipulate that data. Think of creating a "Car" object with properties like color and speed, and methods like "accelerate" and "brake".
Platform-independent Once compiled, Java bytecode can run on any device with a Java Virtual Machine (JVM). You could write a program on a Windows computer and run it on a Mac without needing to make any changes.
Strongly typed Variables in Java need explicit declaration of types, which helps catch errors during development. You'd declare a variable as an "int" (integer) to store whole numbers or as a "String" to store text.
Supports multithreading Java allows for concurrent execution of multiple tasks, which can enhance performance in applications. You could build a chat application where users can send messages while other tasks run in the background.
Robust standard library Java offers a vast collection of pre-built classes and functions for common programming tasks. You might use the "ArrayList" class to store and manipulate a dynamic list of items in your Java program.
Memory management Java automatically deallocates memory for objects that are no longer in use, preventing memory leaks. It ensures that memory is freed up after using temporary variables or objects.
Extensive community support There are plenty of online resources, tutorials, and forums available for learning and troubleshooting Java. You could refer to Java documentation to understand how to use a specific method or class in your program.

Related Reads: Features of JAVA

Applications of Java

To learn more about Java, read our post – What is Java?

What is JavaScript?

Aspect Description
What is Javascript?
A high-level, interpreted programming language
Where is Javascript used?
Primarily for creating dynamic and interactive web pages
Why is Javascript important?
Adds functionality and user experience to websites
How does Javascript work?
Embedded within HTML code and executed by the browser's JavaScript engine
Is Javascript hard to learn?
Considered beginner-friendly with a relatively simple syntax
What are some benefits of using Javascript?
Makes web pages more engaging, efficient, and responsive

JavaScript was developed in 1995 by Brendan Eich. It was created for Netscape 2. In 1997, it became the ECMA-262 standard.

JavaScript (JS) is a dynamically typed programming language (or scripting language). Compared to Java, JavaScript has a less rigid syntax around declaring variables. It does not require the programmer to specify the JavaScript data type that will be stored in a variable. You also don’t need to add classes or functions.

It is interpreted during run time into the machine code and is used for creating interactive web pages. It enhances the user experience of the web page by converting them from static to interactive. The search box on Flipkart and the refresh feature of Instagram are examples of JavaScript.

Javascript follows the rules of client-side or front-end programming. This enables it to run in the user’s web browser without any resources from the webserver. With the introduction to Node.JavaScript (Node.js), it can be used for server-side or backend development as well.

Check out the best JavaScript Courses


Features of Javascript

Feature Description
Client-side scripting JavaScript runs in web browsers and allows you to make websites interactive. It's like adding behavior to web pages. You can validate forms, create animations, and respond to user actions like clicks and keystrokes.
Event handling JavaScript lets you respond to different events on a web page, such as clicks, mouse movements, or keypresses. You can write code to perform specific actions when these events occur, like showing a popup when a button is clicked.
Manipulating the DOM JavaScript can change the structure and content of a web page in real-time. It's like being able to add, remove, or modify elements on a webpage. You can update text, change styles, or even create entire sections of a page dynamically.
Asynchronous programming JavaScript can handle tasks that take time to complete, like fetching data from a server or processing large files, without freezing the entire webpage. It ensures that the user interface remains responsive while these tasks are running.
Cross-browser support JavaScript works consistently across different web browsers, ensuring that your code behaves the same way for all users. Whether they're using Chrome, Firefox, Safari, or Edge, your JavaScript code will run without any compatibility issues.
Libraries and frameworks JavaScript has many pre-built tools, called libraries and frameworks, that help you write code faster and more efficiently. These tools provide ready-made solutions for common tasks, such as building user interfaces or handling data.
Server-side scripting (Node.js) With Node.js, JavaScript can also run on servers, allowing you to build powerful web applications and APIs using the same language on both the client and server sides. It opens up new possibilities for building scalable and efficient web systems.

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Difference Between Java and Javascript - FAQs

What are the primary uses of Java and JavaScript?

  • Java is a general-purpose programming language that is class-based and object-oriented. It is widely used for building enterprise-scale applications, Android apps, and large systems.
  • JavaScript is primarily used for web development, enhancing HTML pages to be dynamic and interactive. It is the scripting language of the web and can also be used on the server-side through environments like Node.js.

How do Java and JavaScript differ in their execution environments?

  • Java code runs on any device that has the Java Virtual Machine (JVM) installed. This makes Java applications platform-independent at the source level.
  • JavaScript code runs in web browsers with a JavaScript engine (like V8 in Chrome or SpiderMonkey in Firefox). It can also run on servers via Node.js.

What type of applications are typically not suitable for Java and JavaScript?

While Java is highly versatile, it might not be the best choice for quick scripting tasks or simple web development due to its more verbose and strict nature. On the other hand, JavaScript is not suitable for applications that require complex back-end processing or extensive use of multi-threading, as it does not natively support these features as efficiently as Java.

Can Java and JavaScript code interact with each other?

Java and JavaScript can interact in web applications where Java may be running on the server side, and JavaScript running on the client side. However, direct interaction in the same application is limited due to their different runtime environments.

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