Java and JavaScript are two significantly different programming languages that are often compared and confused with one another because of their similar names. Both languages are commonly used for web development, but each has its own unique origin, syntax, and uses. In this programming tutorial, we will explore the differences between Java and JavaScript and learn how they differ from one another.
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What are the Differences Between Java and JavaScript?
Below we discuss the differences between Java and JavaScript in great detail. We will be looking at the following elements that define each language:
- History
- Syntax
- Data Types
- Object-oriented Features
- Exception Handling and Errors
- Available Libraries and Frameworks
History
Despite similarities in name, Java and JavaScript are not related and each has their own origin story and history. Java was released in 1995 and created by Sun Microsystems (which was later purchased by the Oracle Corporation), while JavaScript was introduced in 1995 and developed by the now defunct Netscape Communications Corporation.
Java is a general-purpose programming language with object-oriented features, originally created to develop desktop applications. In time it has evolved to be used in the creation of many types of applications, including web development, mobile app development, video game creation, and server-side applications – to name but a few.
In contrast, JavaScript was created to provide interactive and dynamic web content that gets displayed in Internet browsers like Chrome and Safari. JavaScript is also used to create client-side applications, web animations, database driven web apps, and web-based games.
Syntax Differences Between Java and JavaScript
Java and JavaScript, as you might suspect, have different syntax and different rules developers must follow when writing code. Both languages do use curly braces ({}) to define and encapsulate code blocks, but differ in how they use parentheses, semicolons, functions, data types, and keywords.
Java code is usually written in a code editor or an integrated development environment (IDE), such as Notepad++, Eclipse, or Visual Studio Code. Java code gets compiled into bytecode, making it possible to run on any machine with a Java Virtual Machine (JVM) installed. This follows the philosophy of WORA or Write Once, Run Anywhere that has made Java so popular. Java is statically-typed, meaning that the type of a variable must be declared when it is first defined. Java further uses keywords like public, private, and static to define the scope, access, and behavior of variables, methods, and classes.
JavaScript code is normally written directly into an HTML file (.html) or in a separate .js file. JavaScript code gets interpreted by a web browser, and as such, it can run on any platform with a web browser installed. JavaScript is dynamically-typed, meaning variable types are determined at runtime. JavaScript uses keywords including var, let, and const to define both variables and functions.
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Data Types
Java and JavaScript feature different data types, as well as different methods of storing and manipulating data. Java uses primitive data types, including int, double, and boolean, as well as object data types (also known as non-primitive data types), such as String and Date. Java also uses arrays and collections to store multiple sets of values.
JavaScript does feature similar primitive data types as Java, including number, string, and boolean, and also has object data types, like Array and Date. JavaScript does not, however, have a separate data type for characters, nor a specific data type for integer values. JavaScript also uses dynamic typing, meaning the same variable can be assigned different data types at different times, providing a layer of flexibility..
Object-oriented Features
Java and JavaScript both take a different approach to Object-oriented programming concepts. Java is considered by most to be a “pure” OOP language, but this is not quite true. While just about everything in Java is an object, Java (as mentioned above) has primitive data types, which are not technically objects, ruling Java out of being truly OOP. That, and Java lacks support of multiple inheritance, though it can be simulated via the user of interfaces. Java does use classes and objects to encapsulate code, data, and behavior, and it has OOP features including inheritance and polymorphism.
JavaScript, for its part, is considered a hybrid language that supports both procedural and object-oriented approaches to programming. JavaScript has objects as well as functional programming features like closures and higher-order functions. Developers create JavaScript objects using object literals and constructor functions, which can be modified dynamically at runtime.
Exception Handling and Error Handling
Java and JavaScript uses different methods to handle errors and exceptions and each has different mechanisms for detecting and responding to errors in code. Java programmers use try-catch blocks to catch and handle exceptions, which are runtime errors that occur when code is executed. Java also uses checked exceptions, which developers use to explicitly handle or declare exceptions in their code.
JavaScript uses try-catch blocks to catch and handle errors, which are the equivalent of exceptions in Java. Additionally, JavaScript has a mechanism known as error objects, which return information pertaining to the type of error and where it occurred in the code. JavaScript also has event loops for asynchronous programming and non-blocking code execution. This feature allows JavaScript code to run while waiting for a response from a server or waiting on user input, which results in more efficient and responsive code.
Available Libraries and Frameworks
As you might suspect, Java and JavaScript have different libraries and frameworks available to help aid programmers during development. Java has a wide range of built-in libraries, external libraries, and frameworks programmers can take advantages of to create server-side and enterprise-level applications, including Spring, Hibernate, and Apache Struts. Java also benefits from having a number of integrated development environments (IDEs) that are tailored specifically for Java development, such as Eclipse, IntelliJ IDEA, and NetBeans.
You can learn more about Java frameworks in our guide The Best Java Frameworks.
JavaScript also has a number of libraries and frameworks for client-side and web development, including the popular web frameworks jQuery, React, Angular, and Vue.js. JavaScript also has task runners and build tools, like Grunt and Gulp, for task automation. JavaScript developers often use text editors or IDEs like Visual Studio Code, Sublime Text, or Atom to write code in.
You can learn more about JavaScript frameworks in our guide to the Top JavaScript Frameworks.
Final Thoughts on Java versus JavaScript
In this programming tutorial we looked at the differences between the Java and JavaScript programming languages, including their syntax and use cases, as well as their history. We learned that Java is a general-purpose language with Object-oriented features, used for creating server-side applications, mobile apps, video games, desktop applications, and enterprise-level software. We also discovered Java is a statically-typed language with keywords that define the scope, access, and behavior of variables, methods, and classes.
JavaScript, meanwhile, is a client-side language used to create dynamic web content that uses keywords to define variables and functions.
Java and JavaScript also have different methods for incorporating OOP, error handling, and exception handling. Each language has its own set of libraries and frameworks.
In terms of which programming language you should choose, it will depend on your specific needs and preferences. If you want to develop large-scale, Enterprise-level applications, video games, and mobile apps, Java is your choice. If you want to create web-based games and websites with dynamic content, then JavaScript is an excellent choice. Ultimately, since JavaScript is a relatively simple language to learn, there is nothing to say that you cannot learn both languages. This will make you more employable and able to create more powerful, flexible applications for a variety of environments.