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Difference Between Java And JavaScript

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The main difference between Java and JavaScript is the type of language. While java is an object-oriented language that depends on classes and objects, JavaScript remains a scripting language dependent on functions. Java is primarily written for back-end development, while JavaScript is for front-end and back-end development.

Those beginning with the JavaScript will find it amusing the way the JavaScript interpreter interprets the code due to the confusing logic that it follows. The logical operators in JavaScript have a different behavior as compared to other scripting and programming languages.

However, JavaScript has still maintained its popularity over the years, which has only increased over time due to the power it gives to the developers to manipulate a web page on runtime dynamically. That’s why new JavaScript frameworks keep launching frequently.

What Is Java?

Java is a programming language vastly dependent on classes and objects. It uses packages, which act as pre-defined libraries with built-in functions ready to be called. These packages once included in a java program, can be used across the program, reducing writing the code. Java gained a lot of popularity, which made it available in most electronic devices, including DVD players, cars, GPS systems, etc. In fact, Android applications are still heavily written in Java, which is now overtaken by Kotlin by Google gradually.

What Is JavaScript?

JavaScript is a scripting language, which is embedded with markup languages such as HTML. The primary purpose of JavaScript is to manipulate a webpage on runtime based on certain events. JavaScript comes with endless functions, each dedicated to a certain event such as mouse click, button click, page load, page reload, etc. These event functions can be overridden to execute a certain set of code. So, for instance, when the mouse is clicked, it triggers the mouse click event, which is a function. When the function runs, the code inside it is executed. JavaScript resembles a movie script, where the actors act according to what’s written in their part of the script. Moreover, JavaScript has been simplified with the introduction of jquery to better traverse and manipulate DOM objects (Document Object Models) after the webpage loading finishes on the client-end.

Differences Between Java & JavaScript


Java is a programming language, which primarily uses classes, objects, and packages. JavaScript is a scripting language that’s executed upon a certain event, triggering the associated event method.

Code Execution

Java code is compiled by javac (Java Compiler), while JavaScript code is interpreted. As a result, a java program will crash upon execution in case of any errors. On the contrary, a JavaScript program will never disrupt web page execution in case of error. It’s just that the JavaScript code won’t execute and break down at the point with errors, showing no error message on the webpage.

Code File Extension

Java code is saved in a .java file and JavaScript code is saved in a .js file.


Java code is executed on the server while JavaScript code runs on the client’s machine.

Code Logic Consideration

JavaScript considers logical operators slightly differently from java and other programming languages. In JavaScript, the == is used to compare two values, but === is used to compare the data type of two objects. Java doesn’t allow === while JavaScript does.


Java code is saved as byte code after a successful compilation. JavaScript code is saved as a source code on the client-end.

Comparison Chart

Code PlacementIn a .javaIn the <script> tag either in <head> or <body> tag or both
Code LengthJava code is lengthyJavaScript code is short
Code IntegrationWritten and executed separatelyIntegrated with a markup code such as HTML
MultithreadingUses multithreadingNot Available
Front-end Vs. Back-endUsed for back-end onlyUsed for both back-end front-end
Memory ConsumptionUses more memoryUses less memory
Program DevelopmentRequires JDK (Java Development Kit)Simple text editor is enough as the web browsers come with built-in JavaScript execution functionality


Both support return statements, allowing functions to return a value. Statements are terminated with a ; (semi-colon). The curly braces { } define a code block, and any variable declared within the { } is local to the block. The syntax of the if-else statement is mostly similar. 

Frequently Asked Questions

What’s the hardware configuration needed to code in java & JavaScript?

Java programming requires a computer with better hardware configuration as compared to JavaScript programming. Moreover, java demands JDK installation and an IDE (Integrated Development Environment), which is very heavy, hence demanding a heavy hardware configuration. Java code, when compiled, eats up a lot of hardware and resource; hence a good configuration is necessary. Java uses hyperthreading; hence you’ll need a CPU that supports hyperthreading. CPUs with 4 cores allow hyperthreading.

How long does it take to become a JavaScript developer?

JavaScript is tricky and confusing, and becoming a master JavaScript developer should take at least 3-6 months, depending on the time dedicated each day. Daily workout sessions to improve logic and code development further contribute to speedy growth. Becoming a java developer should take almost the same time.

Certain JavaScript frameworks such as Angular has more complex code execution and development style, hence increasing the time required to be a master. On the contrary, certain frameworks such as React.js are somewhat easier, shrinking the training time.

What are some popular and trending JavaScript frameworks?

Some popular and in-demand JavaScript frameworks include React.js, Angular.js, Node.js, jQuery, and Vue.js.

What are the limitations of JavaScript?

Some common limitations include the inability to be executed on the client-side. JavaScript cannot be used for network applications as it’s not designed for that. Moreover, JavaScript cannot use multiprocessors and multithreading, hence limiting its execution speed to some extent.

Is java still demanded?

Java is still in demand, and an average java developer in the United States can earn as high as $110,000 or even more. Some leading organizations that use java include Tesla, Airbnb, PayPal, Google, Spotify, Uber, etc.


By the end of this article, it’s clear that resembling java with JavaScript is totally out of the question as the languages differ heavily on an endless basis. Both the languages have a high popularity and still have a strong future. None of the languages is expected to depreciate anytime in a decade. So, newbies looking to make a fortune as a developer can opt for any of the languages. Several non-java developers criticize java, which must be ignored.


Feel free to comment and discuss about the article in the comment space below if you have any information or remarks to add. If you think we made a mistake, you can also report it there.
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About the Author: Nicolas Seignette

Nicolas Seignette, who holds a scientific baccalaureate, began his studies in mathematics and computer science applied to human and social sciences (MIASHS). He then continued his university studies with a DEUST WMI (Webmaster and Internet professions) at the University of Limoges before finishing his course with a professional license specialized in the IT professions. On 10Differences, he is in charge of the research and the writing of the articles concerning technology, sciences and mathematics.
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