JavaScript in Plain Language (2015)

PART I: AT THE GATES OF ENLIGHTENMENT

“Empty your cup; return to the beginning”.

1.1 The browser interface

Every time we go online we get to use an interface to communicate with the internet. This particular interface is known as “the browser” and its purpose is to translate the incoming data from the outer world into our computer screen. The most popular browsers are Internet Explorer (known as IE and now replaced by Microsoft Edge), Google Chrome, Firefox, Opera and Safari but there are hundreds of other browsers.

Browsers place text and images on the screen based on instructions given by the programmer in a markup language known as HTML. Then this text and images are rearranged or beautified by a styling language called CSS. Finally, the website dynamically interacts with the user viaJavaScript which is the subject of this book.

JavaScript is a computer language designed to interact with and recognized by all browsers. This means that we can create useful programs to run in a browser by writing instructions in JavaScript.

Other programming languages don’t have this capability and they need to run on special platforms acting as further interfaces to the browser and they ask for JavaScript to assist them in this interaction. This is the reason why JavaScript has become the most popular programming language on the internet. Computers use it, websites use it, other software such as for example Photoshop, Word, PDF use it, and last but not least, computer servers are starting to use it on their own backend processing which is great news for the future of JavaScript.

JavaScript can be an easy language when learned the right way, but it can also be a difficult language to learn because it is very dynamic and rules change based on conditions on the ground.

No one can promise to teach you JavaScript since learning is a personal experience. But I can promise you this: read the book in sequence, think about each concept without memorizing it, do all the exercises, and you will be a much better programmer by the time you reach the end of this very short book.

As an author, I may be a programmer or a technical writer, but above all, I am a technical Instructor. My writing experience comes from teaching, coaching, and debugging code from thousands of students. When I write about these concepts I always think about the struggling I’ve experienced when I was learning this material, and the struggle I see on other students when they ask for help. As I write, those problems come to the surface and I try to address them ahead of time in order to prevent you from falling into common traps.