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Java vs. JavaScript: A Complete Comparison

The programming languages Java and JavaScript may sound similar, but they’re not actually related to each other at all. In fact, it’s often said that the name ‘JavaScript’ was a marketing tactic to take advantage of Java’s popularity.

Although both Java and JavaScript are very popular, one may be more suitable than the other for different types of software development projects. So how do you decide which one to learn?

Find out the key differences between Java vs. Javascript here to help you decide which is the right language for you.

Key Differences Between JavaScript vs. Java

What is JavaScript?

JavaScript is the primary language of front-end web development, with most of today’s websites using it along with HTML and CSS to power their client-side. JavaScript can run in browsers on desktops, tablets, smartphones, and more, making it one of the most popular programming languages. 

In the past, most websites were static. JavaScript was created to enable dynamic capabilities like forms, search bars, and other interactive features. This allows companies to develop single-page apps and other modern web experiences.

With the release of Node.js, JavaScript became a full-stack programming language. This runtime engine allows it to execute JavaScript code outside of web browsers. JavaScript web stacks that use Node.js include MEAN (MongoDB, Express, Angular, Node) and MERN (MongoDB, Express, React, Node).

JavaScript is also used for hybrid and cross-platform mobile development. Frameworks like React Native and Ionic help developers build Android and iOS apps using a single JavaScript codebase. For example, React Native renders JavaScript into native code for each platform, making it faster and easier to develop mobile apps that run on any device.

JavaScript is an interpreted language. This means the code is executed by web browsers or runtime engines like Node.js without needing to be pre-compiled. This ‘just-in-time compilation’ makes JavaScript very portable as it’s not compiled into machine code that’s dependent on a specific platform. Other popular interpreted languages include Python, Ruby, and PHP.

Since JavaScript is dynamically typed — meaning the interpreter determines the type of variables at runtime — code written in the language is often more concise. JavaScript contains less repetitive “boilerplate” code, so developers can build programs faster than statically-typed languages.

The most common use cases for JavaScript are:

JavaScript Example

Here’s some simple JavaScript code that prints the numbers 1 through 10:

<!DOCTYPE html>


<title>Treehouse JavaScript example</title>



//Print numbers 1 to 10

        for(var n = 1; n <= 10; n++) {

            document.write(n + ” “);





Advantages of JavaScript

The advantages of JavaScript are:

Disadvantages of JavaScript

The disadvantages of JavaScript are:

What is Java?

Java is a general-purpose programming language that was designed with portability in mind. The language has been around for a long time and is widely used in legacy applications and enterprise systems. It’s also one of the languages supported by the Android mobile operating system and is popular for back-end web development.

Most languages are either interpreted at runtime (like JavaScript) or compiled beforehand (like Go). However, Java is uniquely compiled into bytecode in advance and then interpreted by the Java Virtual Machine (JVM) at runtime. By compiling into bytecode instead of machine code, Java balances the speed of compiled languages with the portability of interpreted languages.

Java is a statically-typed language, so developers need to declare the type of variables when they’re writing the code. For this reason — along with other strict syntax requirements — Java is considered a verbose language that forces developers to write a lot of code. While this may make certain development tasks longer, it can prevent potential issues that otherwise would only be discovered at runtime.

Although later versions of Java have added some functional programming capabilities to the language, it was designed with object-oriented programming in mind. This structures Java programs using classes and objects for clarity and reusability. Most development teams find programs that follow object-oriented design principles to be easier to maintain as their code base grows. 

The most common use cases for Java are:

Java Example

Here’s some simple Java code that prints the numbers 1 through 10:

public class Main {

  public static void main(String[] args) {

    for (int n = 1; n <= 10; n++) {

     System.out.println(n + ” “);




Advantages of Java

The advantages of Java are:

Disadvantages of Java

The disadvantages of Java are:

Is It Easier to Learn Java or JavaScript?

Most programming languages share similar core concepts, so there aren’t dramatic differences in the learning curves of Java or JavaScript. Many students find JavaScript syntax easier to pick up because it’s more concise, but the strict rules of Java make it easier to detect potential issues during development.

That said, think about which language brings you closer to your career aspirations. Many developers find themselves working with multiple programming languages throughout their careers, so learning any language will make it easier to pick up others.

Should I Start With Java or JavaScript?

Whether you choose to start studying Java or JavaScript depends on your interests and career goals. Focus on JavaScript if you want to become a front-end developer, and Java if you’re interested in Android development. Beyond those situations, the best language to learn is more nuanced.

If you’re interested in back-end development, you can learn JavaScript or Java because they’re both useful for server-side applications. However, many back-end developers find it useful to know some JavaScript even if they’re specializing in back-end languages like Java and Python. Knowing both JavaScript and Java deeply can also lead to a career in full-stack development.

Although JavaScript can be used for hybrid mobile development, the vast majority of jobs will be related to web development. In contrast, Java is popular for many different use cases, so there are a lot of software development, mobile development, and web development jobs to choose from.

Start Your Treehouse Free Trial to Learn Java & JavaScript

Now that you know the difference between Java and JavaScript, you can decide which is right for you.

Treehouse offers Tracks for Java and JavaScript. These are sets of courses with guided curriculums and workshops that will teach you basic syntax and core programming concepts. Treehouse also has a Full Stack JavaScript Techdegree that helps you the gain real-world experience you need to land a web developer job.

Start your free trial with Treehouse to begin learning Java, JavaScript, and other tech skills.

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