Java vs. JavaScript: What’s the Difference?

What are the major differences and similarities between Java and JavaScript, and which language is best to learn for your future career in tech? Read on to find out!
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What is Java?

While Java and JavaScript can be easily confused because of their common name, there are key differences between the two languages. Both are considered relatively easy to learn but require time to truly master. Java is an object-oriented programming language created by James Gosling in 1995 and is now maintained by Oracle. It is considered general-purpose and was created with the intent that its code can be written and used anywhere after being compiled into bytecode. 

Any operating system or device that has the Java Virtual Machine (JVM) installed can run and then utilize the programming. This allows the language to run on multiple platforms. It is also a static language so variables do not need to be defined to be used. While many have criticized this as a dying language, year after year, it continues to remain at the top of many rankings as one of the most popular programming languages used. Java is predicted to continue to dominate in 2022.

What is JavaScript

In contrast to Java, JavaScript (JS) is an object-oriented scripting language that is primarily used for front-end web development and can be embedded straight into HTML. 

Facebook, Gmail, YouTube, and Twitter all use JavaScript to create their web pages and make them more interactive. It can be used on the server-side when combined with Node.js which is compatible with major operating systems such as Windows, Linux, Mac OSx, and SunOS. It is great for beginners because the syntax is a relatively easy to learn and a forgiving type of programming. 

It is C-based and exposes beginners to key parts of languages such as variables, types, functions, etc. It is also a dynamic language since variable types and new properties can be added or changed during runtime. JavaScript is also a key player in most websites, working alongside HTML and CSS. JavaScript was named Stack Overflow’s Most Commonly Use Programming Language for the eighth year in 2020. Its popularity and usefulness do not seem to be losing any momentum.

Advantages and Disadvantages of Java and JavaScript 

Knowing that these are two different types of languages with varying uses, it is important to look at the advantages and disadvantages of each programming language.

What are the advantages of Java?

  • It is a secure language.

Since code is grouped, this increases security levels. Explicit pointers are also not used and a security manager is in place for each application with rules for access. Government agencies and investment banking companies lean to this language for this important feature.

  • The language is object-oriented.

Code can be flexible and reused. Many use the slogan “Write once, run anywhere” when it comes to Java.

  • Established libraries and frameworks can cut down on development time.

Pre-written code makes life easier for the programmer.

  • Bugs are found during compiling. 

This is an advantage because errors can be found, and fixed, 

before run time.

  • The language is portable and platform-independent.

Code is designed to be written once and then be used on multiple operating systems and platforms. 

  • It is a high-level programming language.

Since it can be easily read and understood by humans, Java is considered high-level.

  • It automatically manages memory.

A garbage collector — the memory management system — is used to manage memory automatically. The JVM runs the garbage collector when memory is getting low.

  • It can connect to databases.

With Java Database Connectivity (JDBC), Java can connect to 

databases and provide queries.

What are the disadvantages of Java?

  • Java can be relatively slow to start.

Many consider this language slow to start because the JVM has to run first so that Java can be processed on any operating system. All code written in this language has to be compiled and abstracted before being able to run on an operating system. This takes time at the start.

  • It requires a lot of memory space.

The JVM takes memory when it needs to execute logic but still keeps the memory on reserve, even after processing. 

  • It does not have a backup.

Backing up data is not a focus and it operates by using storage space.

  • Codes are long and complex.

While Java works to be more manageable and reusable, this results in codes being longer and more complex and require longer explanations.

What are the advantages of JavaScript?

  • JS is relatively fast to run.

Since most of JavaScript runs on the client-side, it operates quickly. Most browsers do not need to compile JS code before the run.

  • Libraries and frameworks can cut down on development time.

Well-established libraries of code and frameworks are available that lessen the time needed for programmers to create their web designs. Animations, forms, background images, and more can easily be added with established code.

  • It can enhance the user experience by making web applications interactive.

JavaScript can create website features such as drag and drop and sliders.

  • It runs on the client-side web browser without needing to use the server-side.

This is beneficial as it allows for less demand to be put on servers.

What are the disadvantages of JavaScript?

  • Bugs are found at run time.

Debugging does not happen prior to execution and largely depends on the platform over which JS is being executed.

  • It is not very secure.

Execution occurs on the client-side when using JavaScript which 

decreases its level of security.

  • JavaScript has to be written differently for different operating systems. 

This can take time and cause frustrations for the programmer.

Language TypeProgrammingScripting
TIOBE Index Rank
(May 2021)
Main UseBack-endFront-end
Companies That UseAirbnb, Groupon, LinkedIn, eBay, Hubspot, FitbitGroupon, Netflix, Paypal, Facebook, Google, eBay, Uber
Libraries and FrameworksWell-establishedWell-established

Should You Learn Both Java and JavaScript? 

If you are interested in becoming a coder and are trying to decide whether to learn Java and JavaScript, here are some types of projects that incorporate these languages.

What type of projects use Java?

  • Networking
  • Database connectivity
  • GUI based programs
  • Image processing
  • Website development
  • Android mobile application development
  • Big Data analytics
  • Scientific computing

What type of projects use JavaScript?

  • Web development
  • Web applications
  • Server applications
  • Mobile applications
  • Games
  • Front-end technologies

How have companies and developers used Java and JavaScript?

  • Gmail consists of Java code.
  • Airbnb has its back-end written with Java.
  • Facebook uses JavaScript so much that it even created a way to load each piece of a page separately using the language. Facebook developers also created React, a widely used JS library designed to build user interfaces. 
  • Google uses JavaScript every time a user’s search pops up. Google created its own library AngularJS to help build single page applications.
  • The video game Minecraft uses JS in the Minecraft Script Engine.

Career Opportunities 

Career/Job titles for Java and Salary

Careers that utilize Java are in high-demand and compensation reflects this. According to indeed.com, the following average salaries were found for Java-related career fields. Octoparse ranked Java eighth on its list of “15 Highest Paying Programming Languages.”

Career FieldAverage Salary (May 2021)
Java Developer$103,233
Back-end Developer$121,691
Software Architect$135,609
Software Developer$105,708

Java is so popular because it can be written once and used on a variety of operating systems — mobile or desktop. Developers are generally responsible for not only designing Java applications but also implementing and maintaining the applications. They should be able to write efficient and workable code and also test and debug the code. They work with project managers, design leads, and software engineers to plan and deliver projects for their companies. This is one skill for back-end developers to learn in order to write web applications. Software architects and developers utilize Java as a skill to make them more marketable since it is one of the top programming languages in the world.

Career/Job titles for JavaScript and salary

JavaScript is also on Octoparse’s list of “15 Highest Paying Programming Languages,” in 10th place. Since JavaScript is so in-demand, average salaries for jobs that utilize JS are competitive, according to indeed.com.

Career FieldAverage Salary (May 2021)
JavaScript Developer$113,361
Back-end Developer$121,691
Information Security Engineer$103,109
UX Designer$98,002

JavaScript developers and back-end developers utilize JS to create dynamic websites. UX designers that know how to use a programming language like JS become more marketable since they know more about the entire web design process. 

Since JavaScript is widely used, it becomes a target for cyber attacks. Information security engineers need to know how JavaScript works to combat any threats and are in high-demand because so many user interfaces incorporate JS.

As both languages remain two of the most popular programming languages in 2022, it is clear that learning either language (or both) can only be beneficial. Each language has its distinct strengths and for each, it seems that the advantages outweigh any disadvantages. 

With the importance of easy conversion from mobile to desktop systems as well as security, Java will continue to compete as the top programming language. JavaScript won’t remain far behind because of its ease of use for creating powerful web designs that are pleasing for the user. 

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