Darren Jones - Learn to Code With JavaScript

I still remember my first ever computer: it was an Acorn Electron, and I loved using it to play games such as Sphinx Adventure (a text-based adventure), Starship Command (a hard-as-nails shoot-em-up) and Chuckie Egg (pure platform action). But the real fun started when I realized that I could write my own code in a language called BASIC. My initial thoughts were that it had been named ironically, as it appeared to be anything but basic. It had line numbers that went up in multiples of ten and strange-sounding commands such as GOTO, REM and CLS that just looked like gobbledygook at first. But with lots of practice (and many mistakes), it started to make sense and I became fascinated by how the code allowed me to control what the computer did. I would spend hours copying code examples out of magazines (yes, it was that long ago!) and then play around making my own modifications. It was this experimentation and tinkering with code that helped me understand how it worked. I had been well and truly bitten by the coding bug.

My enjoyment of coding comes from the fact that it requires you to follow the precise rules of the programming language while also encouraging you to think creatively to achieve your desired outcome. The essence of coding is turning the abstract into the practical. When I set about writing this book, my aim was to introduce the basic concepts of coding and back the theory up with plenty of practical examples. Each chapter ends with coding challenges that will help consolidate your understanding. I encourage you to really dig into these challenges by not only trying to complete them, but also trying to extend them with your own modifications.

It was always games that I wanted to program, and Ive tried to make as many of the challenges in the book as fun as possible, both to code and to play. And by the end of the book, youll have coded a couple of fully playable games. Youll also have the foundations in place for creating interactive websites and be on the right path to writing full-scale applications.

Programming is a creative endeavor; its fundamentally about creating things. You need your code to be precise and concise, but you also need to inject it with some flair to make it come alive. This mix of precision and ingenuity is what continues to make coding enjoyable for me, many years after starting out on my Acorn Electron. My hope is that this book will inspire you to start coding and that youll continue to enjoy it for a long time after youve finished reading the last page.

This book is for people with no prior programming experience who would like to learn how to code. We use JavaScript in this book to teach you, so at the end you'll have a good understanding of JavaScript, but you can apply the principles youve learned to other programing languages, too.

Code in this book is displayed using a fixed-width font, like so:

Youll notice that weve used certain layout styles throughout this book to signify different types of information. Look out for the following items.

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• books@sitepoint.com is our email address, should you need to contact us to report a problem, or for any other reason.

So you want to learn to program? Youve made a good decision. Programming is a fantastic skill to learn, and its great fun. It can be used to build the next generation of apps, hack a Raspberry Pi or Arduino, write the latest blockbuster gamesand a ton of other things. In fact, once you learn how to program, the only limit is your imagination.

In this chapter, well briefly survey the history of programming, look into what a computer program actually is, and then introduce the JavaScript programming language, which well be using to learn how to program.

Well also be jumping right in and getting started with some programming, writing not one, but two programs in JavaScript!

Heres what this chapter will cover: