JavaScript (JS) is a lightweight, interpreted, or just-in-time compiled programming language with first-class functions. While it is most well-known as the scripting language for Web pages, many non-browser environments also use it, such as Node.js, Apache CouchDB and Adobe Acrobat. JavaScript is a prototype-based, multi-paradigm, single-threaded, dynamic language, supporting object-oriented, imperative, and declarative (e.g. functional programming) styles.
Woo, that is a hell of a definition. So let's minimise it a little bit and break it down individually for better understanding.
Javascript is a high-level, object-oriented, multi-paradigm, programming language
Any programming language is interpreted as a set of instructions given to a computer to do something. Of course, that is our primary goal in using javascript.
Then I say javascript is a high-level language, which means we don't have to worry about complex stuff like memory management while it is running our programme. In javascript, there are a lot of abstractions over such minor details, and we don't have to worry about those. And this makes the language a lot easier to write and learn.
Next, I say that javascript is an Object-Oriented language; all that means is that the language is mainly based on the concepts of objects for storing most kinds of data. And of course, we will learn all about object-oriented programming throughout this course. So don't worry if you are not familiar with the term object.
It is also a multi-paradigm language, meaning that it is so flexible and versatile that we can use all kinds of different programming styles. Such as imperative and declarative programming. These different styles are unique ways of structuring our code; again, you will learn about this throughout this course.
Also, in computing, just-in-time (JIT) compilation (also dynamic translation or run-time compilations) is a way of executing computer code that involves compilation during the execution of a program (at run time) rather than before execution.
To break it further, let me give an example to make you understand from the knowledge you already have. Nowadays, you might come across apps with a mobile application and a browser-based website, which looks and functions similarly in the majority of the cases.
For instance, be it Youtube or Facebook or Netflix, these provide you with some mobile application and browser-based applications, ultimately providing you with the same experience and services. But there is a catch. In the case of a mobile application, you are downloading the application and installing them individually, but when it comes to the web application, you are not installing anything new. So something is going on in the background of the web browser in real-time while loading the application. This is taken care of by Javascript; this is also one of the main reasons you will find many javascript tutorials based on web development.
Even though the above example is also specific to web applications, this course aims to learn and apply javascript to various scenarios. Even though this is not a holistic way of terming javascript, for now, this is an excellent intro to continue with the rest of the course; as we proceed, we will develop on our existing knowledge so that I can explain further. If you are eager to learn more about the definition, I suggest you refer to this.
Again, you will learn all about these throughout this course and eventually get the hang of it.
