Java Vs JavaScript: What Are The Important Differences

In this Java vs JavaScript tutorial let’s discuss major differences between Java and an important scripting language JavaScript with simple examples:

Java is an object-oriented programming language and runs on a Java Virtual Machine (JVM) that helps you to create programs that are platform-independent (Write once, Run anywhere –WORA). Java is used for both client-side as well as server-side programming but in web applications, you will find its main use in server-side programming.

JavaScript has no relation with Java except for the part of the name. Java and JavaScript are two different languages. Unlike Java, JavaScript is a lightweight scripting language.

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Java vs JavaScript

JavaScript is used to make web pages designed using HTML more interactive and dynamic. At the same time given an HTML page, you can add validation to it using JavaScript. JavaScript is commonly known as a “Browser” language.

In this tutorial, we will discuss the major differences between Java and JavaScript and also discuss some of the drawbacks of both the languages.

Let’s explore the key differences between Java and JavaScript.

Java Vs JavaScript: Key Differences

Key DifferencesJavaJavaScript
HistoryJava was developed by sun microsystems in 1995 and later taken over by oracle.JavaScript was developed by Netscape in 1990s.
OOPSJava is an object oriented programming language.JavaScript is an object based scripting language.
Running platformJava requires JDK and JRE to be installed before executing programs/applications. JavaScript does not require any initial setup or installation and runs within a browser.
Learning curveJava is a vast language and has loads of documentation, online articles, books, communities; forums etc. and you can learn it easily.JavaScript is comparatively smaller and also has vast online documentation; forums etc. and are easy to learn.
File extensionJava program files have an extension “.Java”.JavaScript code files has “.js” extension
CompilationJava is a programming language and hence Java programs are compiled as well as interpreted.JavaScript is a scripting language with a plain code in text format and is interpreted.
TypingJava is strongly typed language and variables or other objects should be declared before using them. You can declare a variable in Java as below:
int sum = 10;
JavaScript is a weakly typed language and is easier as far as rules are concerned. In JavaScript the variable is declared as: var sum = 10;
Note that there is no exact type associated.
Object modelIn Java everything is an object and you cannot write a single line of code without creating a class. JavaScript objects use prototype-based design.
SyntaxJava has syntax similar to C /C++ languages. Everything in Java is in terms of classes and objects.JavaScript syntax is similar to C but the naming conventions are like Java.
ScopingJava has blocks (denoted by {}) that defines scope and variable ceases to exist out of the block. JavaScript is mostly embedded in HTML and CSS; so its scope is limited to functions.
concurrencyJava offers concurrency through threadsIn JavaScript you have events that can simulate concurrency.
PerformanceJava gives better and faster performance mainly because factors like static typing, JVM etc. JavaScript is dynamically typed and most validation is at runtime making it slower.

JavaScript Vs Java: Code Examples

#1) Syntax

A sample Java program syntax is given below.

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

Sample syntax of a JavaScript program is given below:

<title>JavaScript Code Follows:</title>
alert(“Hello World!!”);

As we can see from the above code samples, while in Java we can have a standalone program, we cannot have such a standalone program using JavaScript. We enclose the JavaScript code inside the <script> </script> tag in an HTML component.

#2) Object Model

As mentioned in the differences above, everything in Java is an Object. So even to write a simple program, we need a class as shown below.

Class myclass{
Int sum;
    Void printFunct (){

JavaScript has a prototype-based design as shown below:

var car = {type:"Alto", model:"K10", color:"silver"};

This is the way in which an object is defined in JS.

#3) Variable Scope

Consider the following example in Java:

void myfunction (){
   for (int i=0;i&lt;5;i++){

In the above example, the scope of variable i is limited only to for loop ({}).

Consider the following piece of code in JavaScript.

function myFunction(p1) {
return p1 *10; }

In the above function, p1 will cease to exist once out of the function myFunction.

So as JavaScript code is mostly embedded in <script></script> tags, the scope of variables is limited to functions only unlike Java, in which variables have method scope, block scope, etc.

Further Reading =>> Javascript Vs Python

More Differences

#1) Popularity

In 2019, Java has been voted as the second most popular language. JavaScript as well is one of the popular languages among programmers. But ultimately it’s the requirement that scores over everything else.

If you are developing applications that require extensive client-side validation and interaction and it is a browser-based application, then you should definitely prefer JavaScript. For desktop or mobile-based GUI applications, Java is more popular among programmers.

#2) Mobile Application

Java is supported by mobile operating systems like Android and Symbian. Some of the older mobiles also have the software developed in Java.

JavaScript allows you to develop mobile applications but the feature support is limited and you will have to use any third-party tools.

#3) Support

Almost all operating systems support Java programming language.

Most of the web browsers support JavaScript irrespective of the operating systems that the web browsers are operating on.

#4) Future

Java and JavaScript are both popular languages. JavaScript is mostly used in browsers for frontend and will definitely be around for a decade or two as most of the browsers, old as well as new, support JavaScript.

Java is mostly used for backend, and is also very popular for its features and is expected to have a bright future.

#5) Jobs And Salary

At present, the job market has demand for Java as it is a general-purpose programming language and you can develop a variety of applications using it. The average rate for Java developers in the US market is $60/hour.

JavaScript is a client-side scripting language and has limited uses. It cannot develop standalone applications like Java. But having said that in the US market, JavaScript developer also fetches the same price. Also as most of the browsers support JavaScript, it is also going to be in demand.

Java Vs JavaScript: Tabular Representation

Comparison ParametersJavaJavaScript
HistoryDeveloped by sun microsystemsDeveloped by Netscape
OOPSJava is an object-oriented programming languageJavaScript is an object-based scripting language
Running PlatformRequired JDK and JRE to be installed on a system to develop and execute Java programsRuns within HTML or CSS code within the browser.
Learning curveEasy to learnVast documentation, easy to learn
TypingStatically/strongly typedDynamically/weakly typed
Object modelEverything is object-basedSupports prototype-model
SyntaxSimilar to C/C++ languagesSimilar to C but a naming convention like Java
ScopingHas block-level scopeHas function level scope
Concurrency Supports concurrency through threads
Performance Higher performanceLower performance
Popularity Highhigh
Mobile application Used extensivelyHave limitations
SupportSupported by almost all operating systemSupported by all the web browsers
FutureHas a bright futureHas a good future
Jobs and salaryIn demand and offers a high salaryMostly in demand and has a higher salary.


We have seen various differences between Java and JavaScript languages. Now let’s discuss the drawbacks of these languages.

Disadvantages of Java:

#1) Memory: Java programs consume more memory when compared to other higher-level languages like C/C++. All Java programs are executed on top of a Virtual Machine that consumes more memory.

#2) Garbage collection: Java has automatic garbage collection and has no control over it as a programmer cannot do anything about it in the program.

#3) Hardware cost: Java Runtime Environment consists of additional Java Virtual Machine which increases memory requirement and thereby the cost of hardware.

#4) Low-level programming: Java does not provide any support for low-level programming like C/C++. We cannot access system-level resources with Java.

#5) GUI Features: Java supports GUI features but is limited.

Drawbacks of JavaScript:

#1) Security on the client-side: This is one of the major disadvantages of JavaScript as the script can be viewed by the user as well. Thus anyone can use it for non-ethical purposes.

#2) Different browser support: Different browsers interpret JavaScript differently. Hence before publishing, you should run the code on various platforms. Additionally, the older browsers may not support new functions and you also need to check these.

#3) No debugging facility: Due to the lack of proper debugging facilities, it becomes difficult for developers to detect the problem in the code.

#4) No multiple inheritances: JavaScript only supports single inheritance. Applications requiring other types of inheritance cannot be developed.

#5) Rendering errors: The browser can entirely stop rendering the JavaScript code because of a single code error. To the end-user, it is as good as JavaScript is not at all present. This thereby results in misinformation.

Frequently Asked Questions

Q #1) Is JavaScript easier to learn than Java?

Answer: JavaScript has a smaller set of commands when compared to Java and also the syntax is not as strict as Java. Hence it’s a lot easier especially for a novice programmer to learn JavaScript than Java.

Also, JavaScript code is almost text-like, thus anyone can understand it quickly.

Q #2) Which is better Python or JavaScript?

Answer: Python is better. At present Python is in demand and has a good market in the IT industry mainly because of its machine learning and data science capabilities.

Python is easier to maintain. JavaScript is poor to maintain. Having said that, JavaScript is also emerging, and without a doubt, it is the most used language in client-side scripting.

It all depends on the developer’s requirement and it’s the developer who will choose a suitable language that suits his/her needs.

Q #3) Do I need to know Java to learn JavaScript?

Answer: No. There is nothing common between Java and JavaScript. Only knowledge of general programming is enough to learn JavaScript.

Q #4) Is JavaScript faster than Python?

Answer: It totally depends on which implementations of JavaScript or Python you are using. For example, nodeJS is faster than the other implementations of JavaScript. Similarly, PyPy implementation is much faster than JavaScript.

Q #5) Is JavaScript used for the backend?

Answer: Yes. JavaScript is used both for the front end as well as backend. But it is a very poor language for the backend as it is weakly typed and doesn’t have powerful features.


We have discussed the detailed differences between Java and JavaScript in this tutorial with examples. We have also discussed some drawbacks of both the languages in order to evaluate the importance of each language.

Suggested reading =>>  JavaScript vs TypeScript

While Java is a general programming language that has uses in a wide variety of applications, JavaScript is basically a scripting language that is embedded in a browser code like HTML or CSS. We cannot execute JavaScript code as a standalone application, unlike Java.

However, JavaScript is still a powerful language although it is very difficult to maintain. Almost all the browsers support JavaScript and it is a powerful language for making web pages interactive and validating the data.

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