Difference Between Java and JavaScript

Basis Of Distinction

JAVA

JAVA-SCRIPT

Definition

A general-purpose computer programming language that is concurrent, class based, object-oriented and specifically designed to have as implementation dependencies as possible.

A high level, interpreted programming language that can be characterized as dynamic, weekly typed, prototype-based and multiple-paradigm.

Development

Developed By James Gosling in 1995 at Sun Microsystems later occupied by Oracle.

Developed By Brendan Eich in 1995 at Netscape and originally as LiveScript.

Language

Java is an object-oriented programming language.

JavaScript Is an Object-based scripting language.

File Extension

It has a file Extension “.java” .

It has a file Extension”.js” .

Type Checking

Java is Static, and a strongly-typed language.

JavaScript is dynamic, and a weekly-typed language.

Objects

Objects In Java are class-based.

Objects in JavaScript are prototype-based.

Object Inheritance

It is an OOP language and  supports all  inheritance techniques.

It does not support certain techniques like multiple inheritance.

Variable Definition

Variables and their types should be declared before using them in the program.

Variables can be declared and types can be assigned at the time of execution,

Scope of Variable

Java variables have a block-based scope. They are out of scope when the control comes out of a code-block.

JavaScript variables have a function-based scope.

Function Overloading

A Java code can have two or more functions with the same name to execute different tasks.

JavaScript doesn’t support function overloading.

Syntax

Java language syntax is similar to C or C++ programming language. Java program will be in objects and classes. Data types must be declared.

JavaScript is pretty similar to the C programming language but naming conventions are similar to java programming language. Data types not declared.

Closure

A function in Java can’t be passed as an argument to  another function.

JavaScript supports closure.

Code Execution

Java code is compiled into bytecode, which is then interpreted at the time of execution.

JavaScript is interpreted and executed by the browser.

Execution Environment

Java code is compiled on the server before executing it on the client platform.

JavaScript is interpreted within a web browser.

Threading

It is a multi-threaded program.

It is a single-threaded program.

Security

Java source code is hidden.

JavaScript code is written in plain text.

Type of language

Static

Dynamic

TOBIE rating

1

6

Platform Dependency

Java code exists as a standalone program.

JavaScript code is contained within a webpage, integrated with HTML code.

Platform Portability

Java codes can be written once and ported on multiple platforms.

JavaScript codes vary with the execution platform.

Running platform

Java applications and programs run in java virtual machine (JVM) which require installing Java Runtime Environment (JRE) and Java development Kit(JDK) on a system,

JS web applications run on a web browser and no need for any initial setup.

Concurrency

It has a thread-based approach to concurrency.

It has an event-based approach to concurrency.

Memory Usage

Java programs use more memory for running.

JavaScript Programs are lightweight.

Development tool

Java programs require a Java Development Kit.

JavaScript codes can be written in any simple text editor.

Used For

Used to develop desktop , web and mobile application.

Used to develop web application.

Compilation

Java programs are compiled and interpreted as it is a programming language.

JavaScript is interpreted as it is a scripting language with a plain text code.

After Compilation

Java application can run in any virtual machine (JVM) or browser.

JavaScript code used to run only in browser, but now it can run on server via Node.js .

Learning Curve

Java has extensive documentation, online sources, online forums, communities from which one can learn easily. If we want to build applications and programming we can learn Java.

JavaScript also has an extensive list of online source, documentation, online forum and communities by which one can easily learn as we can see its execution in the browser immediately.

Code Type

Object-oriented. Applets consist of object classes with inheritance.

Object-based. Codes uses built in, extensible objects but not uses any classes or inheritance.

Support

It is supported by most of the operating system.

JavaScript  is supported by many web browsers that come with different OS and web developers can directly create script.

Mobile Applications

Old applications of mobile phones are mostly written in Java and smartphones platforms like Android and Symbian also support Java.

Using JavaScript we can develop mobile applications but there are few limitations as we need to use 3^rd party tools to convert it to native programming code which mobile platform/OS can execute.

Key Features

Great libraries, widely used, excellent tooling.

Can be used in front-end/back-end, it’s everywhere, lots of great framework.

Scope

It is available almost everywhere ans it’s an independent language that can run on different operating system. Also, Java uses block=based scoping where variable goes out of scope once control comes out of a block.

JavaScript is mostly used on different web browser and completely relies on CSS and HTML due to which it’s not available globally. JS uses function-based scoping as the variable can be accessed in function.

Companies using the technology

Airbnb, uber technologies, netflix, instagram.

Reddit, ebay,cousera, discord.

Code

class A {

 public static void main(String args[]){

     System.out.println("Hello World");

 }

}

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