The main difference between Java and JavaScript is that the programming languages are primarily used for different purposes. Although they sound very similar there are not many similarities between them they are significantly different.
Java is essentially used as a general-purpose programming language while JavaScript is used as a client-side scripting language that allows you to implement complex features on web pages. Java is both a compiled and interpreted language while the browser interprets JavaScript. In its most common form, JavaScript resides inside HTML documents and can provide levels of interactivity to web pages that are not achievable with just simple HTML. Compiled Java code can run on all platforms that support Java as it is an object-oriented programming language and has a virtual machine platform that allows you to create compiled programs that run on nearly every platform. Java features most prominently as a server-side language and the programming language of choice for mobile apps on the Android platform. When Java was first released in 1991, it was being used to program electronics such as VCRs. JavaScript was introduced to be used with Java as a client-side scripting language that could run in the browser without having to be compiled. Let’s have a closer look at some of the main differences between these two languages.
Major differences:
Compiled vs. Interpreted.
Java is considered a compiled programming language. JavaScript is considered an interpreted scripting language. The difference is in the implementation. Java is compiled into bytecode and runs on a virtual machine, whereas JavaScript can be interpreted directly by a browser in the syntax it is written.
Static vs Dynamic Type Checking.
Java uses static type checking, where the type of a variable is checked at compile time. The programmer must specify the type (integer, double, string, etc.) of any variable that they create. JavaScript, like most scripting languages, uses dynamic typing, where type safety is verified at runtime. It is not required for a programmer to specify the type of any variable they create. The primary advantage of static type checking is that type errors are caught early in development, and because the compiler knows exactly what data types are being used, code typically executes faster or uses less memory. The primary advantage of dynamic type checking is programmer productivity.
Concurrency.
The ability to handle the execution of many instruction sequences at the same time is handled very differently between Java and JavaScript. Java makes use of multiple threads to perform tasks in parallel. JavaScript handles concurrency on one main thread of execution via a queue system called the event loop, and a forking system called Node Clustering. For most use-cases, both methods work just fine, but Java is generally faster because the thread to thread memory sharing is much faster than interprocess communication (IPC).
Hopefully, this article strengthens your knowledge of the difference between Java and JavaScript. Using JavaScript is one of the key topics in our web development course. To find out more click HERE!
