It appears you have decided to start learning JavaScript. Excellent choice! JavaScript

is a programming language that can be used on both the server side and client side of

applications. The server side of an application is the backend logic that usually runs

on computers in data centers and interacts with the database, while the client side is

what runs on the device of the user, often the browser for JavaScript.

It is not unlikely that you have used functionality written in JavaScript. If you have

used a web browser, such as Chrome, Firefox, Safari, or Edge, then you definitely

have. JavaScript is all over the web. If you enter a web page and it asks you to

accept cookies and you click OK, the popup disappears. This is JavaScript in action.

And if you want to navigate a website and a sub-menu opens up, that means more

JavaScript. Often, when you filter products in a web shop, this involves JavaScript.

And what about these chats that start talking to you after you have been on a

website for a certain number of seconds? Well, you guessed it—JavaScript!

Pretty much any interaction we have with web pages is because of JavaScript; the

buttons you are clicking, birthday cards you are creating, and calculations you are

doing. Anything that requires more than a static web page needs JavaScript.

In this chapter, we will cover the following topics:

•Why should you learn JavaScript?

•Setting up your environment

•How does the browser understand JavaScript?