Java Tutorial



Java Tutorial

Java vs. JavaScript


‘Java vs. JavaScript’ has always been debated among developers in various fields, especially software and application development. Java is a highly scalable object-oriented language. It is a go-to choice for experts developing corporate applications. 

JavaScript, on the other hand, is a dynamic scripting language. Deemed as the language of the internet. It has enabled developers to create dynamic and interactive web applications. 

Understanding the distinction between Java and JavaScript is crucial due to their different purposes and functionalities. Knowing the difference helps choose the appropriate language for a specific task or project. Understanding their disparities in syntax, programming paradigms, and execution environments allows developers to make informed decisions, select the right tools, and write efficient and maintainable code. 


Here, you will learn the difference in the individual characteristics, strengths, and implementation areas in Java vs. JavaScript. After going through this tutorial, you will know the unique attributes that make each language indispensable in software development.

Features of JavaScript 

JavaScript enables web developers to build dynamic, engaging, cross-platform web applications. It possesses a range of powerful features that prove invaluable in web development. 

Some of them have been listed below:

  • It facilitates interactive web pages by facilitating dynamic content updates and user engagement.

  • Running on the client side, JavaScript ensures responsive experiences without relying heavily on server interactions.

  • It enables convenient manipulation of the HTML structure through the Document Object Model (DOM). 

  • JavaScript supports asynchronous programming, enabling handling time-consuming tasks without hindering the user interface. 

  • It enjoys wide support across web browsers and seamlessly integrates with HTML and CSS. 

  • JavaScript's extensive library and framework ecosystem further simplify development. 

  • It can be easily used for server-side programming with Node.js. 

Java vs. JavaScript: Key Differences 

Some of the key differences when it comes to Java vs. JavaScript have been elucidated in the table below:




Language Type

Java is a compiled programming language.

JavaScript is an interpreted scripting language.


Java programs run on the Java Virtual Machine (JVM).

JavaScript code runs within a web browser.

Language Paradigm

Java follows an object-oriented programming paradigm.

JavaScript is a multi-paradigm language supporting procedural, object-oriented, and functional programming.

Use Cases

Java is commonly used for enterprise applications, Android development, and server-side programming.

JavaScript is widely used for web development, front-end development, and browser automation.


Java uses a C-style syntax and employs static typing.

JavaScript also uses a C-style syntax but employs dynamic typing.

Platform Dependency

Java is platform-specific and requires the JVM for execution.

JavaScript is platform-independent and executes within web browsers.

Memory Management

Java features automatic garbage collection for memory management.

JavaScript also utilizes automatic garbage collection for memory management.


Java supports multithreading for concurrent programming.

JavaScript supports asynchronous programming using callbacks, Promises, and async/await.

Error Handling

Java includes checked exceptions and relies on try-catch blocks for error handling.

JavaScript uses exceptions and try-catch blocks for error handling.

Standard Library

Java has a large and comprehensive standard library that provides a wide range of built-in functionalities.

JavaScript has a smaller standard library compared to Java.

Community Support

Java has a strong community with extensive documentation and resources available.

JavaScript has a vast and active developer community, providing ample support and resources.

Back-End Development

Java is widely used for building server-side applications and has numerous frameworks and tools available.

JavaScript can be used for server-side programming with technologies like Node.js.

Mobile Development

Java is commonly used for developing native Android applications.

JavaScript can be used for mobile development using frameworks like React Native for cross-platform applications.

Java vs. JavaScript Syntax

Syntax Style

Java: Java follows a statically-typed syntax, where variable types are explicitly declared.

JavaScript: JavaScript follows a dynamically-typed syntax, where variable types are inferred at runtime.

Class-Based vs. Prototype-Based

Java: Java is a class-based language where classes are used to define objects and their behaviors.

JavaScript: JavaScript is a prototype-based language where objects are created from existing objects as prototypes.

Object Declaration

Java: In Java, objects are typically declared using the new keyword and the class constructor.


Person person = new Person();

JavaScript: In JavaScript, objects can be created using object literal notation {}, constructors, or the new keyword.


var person = {}; = "John";
person.age = 25;

Variable Declaration

Java: Variables in Java must be declared with a specific type (int, char, etc.) before they can be used.


int age = 25;
String name = "John";

JavaScript: Variables in JavaScript can be declared using the var, let, or const keywords, and their types can be changed dynamically.


var age = 25;
let name = "John";

Method Invocation

Java: In Java, methods are invoked using the dot notation object.method().



JavaScript: In JavaScript, methods can be invoked using the dot notation or by directly calling the function method().



Memory Management

Java: Java has automatic memory management through garbage collection. Objects are allocated on the heap and are automatically deallocated when no longer referenced.

JavaScript: JavaScript also has automatic memory management but uses garbage collection with a different approach. It uses a combination of a mark-and-sweep algorithm and reference counting for memory management.

Exception Handling

Java: Java has built-in exception handling mechanisms using the try, catch, finally, and throw keywords.


try {
    // Code that may throw an exception
    int result = divide(10, 0);
    System.out.println("Result: " + result); // This line won't be executed
} catch (ArithmeticException e) {
    // Handling specific exception: division by zero
    System.out.println("Error: Division by zero");
} catch (Exception e) {
    // Handling general exception
    System.out.println("Error occurred");
} finally {
    // Code that executes regardless of an exception
    System.out.println("Finally block executed");

// Method that performs division and may throw an exception
public static int divide(int dividend, int divisor) throws ArithmeticException {
    return dividend / divisor;

In this example, we have a try block that contains code that may throw an exception. The catch blocks handle different types of exceptions. The finally block is optional but is commonly used for cleanup tasks. The divide() method is declared with the throws keyword to indicate that it may throw an ArithmeticException.

JavaScript: JavaScript also supports exception handling but uses a different approach than Java. In JavaScript, exceptions are caught using try and catch blocks, similar to Java. However, JavaScript does not have a finally block. 


try {
    // Code that may throw an exception
    let result = divide(10, 0);
    console.log("Result: " + result); // This line won't be executed
} catch (error) {
    // Handling the exception
    console.log("Error: " + error.message);

// Function that performs division and may throw an exception
function divide(dividend, divisor) {
    if (divisor === 0) {
        throw new Error("Division by zero");
    return dividend / divisor;

In JavaScript, we use the try block to enclose the code that may throw an exception, and the catch block to catch and handle the exception. In this example, we throw a custom Error object when division by zero occurs, and we catch the exception in the catch block.

We should also note that JavaScript supports the throw statement to throw exceptions at specific points in the code manually.

Java vs. JavaScript Examples


In the case of Java, we can use System.out.println() to print “Hello, world!”.

public class upGradTutorials {
    public static void main(String[] args) {
        System.out.println("Hello, world!");

In this example, we have a public class named upGradTutorials. In Java, a class is a blueprint or template for creating objects. It encapsulates the data and behavior that define a particular entity. The class name needs to match the file name in which it is defined.

Within the upGradTutorials class, we have a public static method called main. The main method serves as the entry point for the program execution. It is a special method that is automatically called when the program starts running. The main method takes an array of strings (args) as a parameter, allowing command-line arguments to be passed to the program if needed.

Inside the main method, we use the System.out.println() statement to print the message "Hello, world!" to the console. The println() method is a utility provided by the System.out object, representing the standard output stream. It displays the given message, followed by a new line, on the console.

When you run this Java program, the main method will be executed. As a result, the message "Hello, world!" will be displayed in the console. This program is a common introductory example showcasing a Java program's fundamental syntax and structure.

By modifying the message or adding additional code within the main method, you can extend the program's functionality to perform various tasks or calculations according to your requirements.


In the case of JavaScript, we can use console.log("Hello, world!"); to print “Hello, world!”.

To run the above JavaScript program, you can create an HTML file (e.g., index.html) and include the following code within the <script> tag:

console.log("Hello, world!");

Once we open the HTML file in a web browser, and you will see the output "Hello, world!" in the browser's console. The <script> tag is an HTML element that embeds or defines client-side JavaScript code within an HTML document. It serves as a container for JavaScript code that the web browser should execute.

Inside the <script> tags, we have the JavaScript code console.log("Hello, world!");. This line uses the console.log() function to print the message "Hello, world!" to the browser's console.

The console.log() function is a built-in function provided by web browsers that allow you to output messages or values to the browser's developer console. It is primarily used for debugging purposes or displaying information during development. In this case, it displays "Hello, world!".

When you run this JavaScript program in a web browser, the console.log() statement will be executed, and the message "Hello, world!" will be printed on the console.


In conclusion, Java and JavaScript are two distinct programming languages with their own unique features and use cases. Java excels in enterprise applications and server-side programming, while JavaScript shines in web development and front-end applications. Understanding their differences helps developers make informed decisions and leverage their strengths for optimal software development.

If you are still wondering, ‘Should I learn Java or JavaScript?’, consider signing up for a professional software development course to gain an in-depth understanding of Java and JavaScript. upGrad offers some of the choicest professional courses from the top universities. Check them out today! 


  1. Which is the better choice when it comes to Java vs. JavaScript?

The choice between Java and JavaScript depends on the project's requirements and use case.

  1. Is Java the same as JavaScript?

No, Java and JavaScript are different programming languages with distinct syntaxes, purposes, and use cases.

  1. Is learning Java difficult?

The difficulty of learning Java can vary depending on individual learning abilities and prior programming experience.

  1. What is Java vs. Python salary in India?

The average annual salary of a Junior Java Developer in India is Rs.4,34,089. A Junior Python Developer in India earns about Rs.2,87,951 per year.

  1. What is Java vs. JavaScript salary in India?

While a Junior Java Developer in India earns an average annual salary of Rs.4,34,089, a JavaScript Developer’s average base salary is about Rs.5,77,514 annually. Comparing Java vs. JavaScript vs. Python salaries can give you a better understanding of their scope and demand.

Leave a Reply

Your email address will not be published. Required fields are marked *