Speaking JavaScript (2014)

Preface

Due to its prevalence on the Web and other factors, JavaScript has become hard to avoid. That doesn’t mean that it is well liked, though. With this book, I’m hoping to convince you that, while you do have to accept a fair amount of quirks when using it, JavaScript is a decent language that makes you very productive and can be fun to program in.

Even though I have followed its development since its birth, it took me a long time to warm up to JavaScript. However, when I finally did, it turned out that my prior experience had already prepared me well, because I had worked with Scheme, Java (including GWT), Python, Perl, and Self (all of which have influenced JavaScript).

In 2010, I became aware of Node.js, which gave me hope that I’d eventually be able to use JavaScript on both server and client. As a consequence, I switched to JavaScript as my primary programming language. While learning it, I started writing a book chronicling my discoveries. This is the book you are currently reading. On my blog, I published parts of the book and other material on JavaScript. That helped me in several ways: the positive reaction encouraged me to keep going and made writing this book less lonely; comments to blog posts gave me additional information and tips (as acknowledged everywhere in this book); and it made people aware of my work, which eventually led to O’Reilly publishing this book.

Therefore, this book has been over three years in the making. It has profited from this long gestation period, during which I continually refined its contents. I’m glad that the book is finally finished and hope that people will find it useful for learning JavaScript. O’Reilly has agreed to make it available to be read online, for free, which should help make it accessible to a broad audience.

What You Need to Know About This Book

Is this book for you? The following items can help you determine that:

Who this book is for

This book has been written for programmers, by a programmer. So, in order to understand it, you should already know object-oriented programming, for example, via a mainstream programming language such as Java, PHP, C++, Python, Ruby, Objective-C, C#, or Perl.

Thus, the book’s target audience is programmers who want to learn JavaScript quickly and properly, and JavaScript programmers who want to deepen their skills and/or look up specific topics.

What’s not covered

This book focuses on the JavaScript language proper. For example, you won’t find information on programming web browsers (DOM, asynchronous programming, etc.). However, Chapter 33 points to relevant material.

How this book is organized

This book is divided into four parts, but the main two are:

§ JavaScript Quick Start

§ JavaScript in Depth

These parts are completely independent! You can treat them as if they were separate books: the former is more like a guide, the latter is more like a reference. The Four Parts of This Book tells you more about the structure of this book.

What JavaScript version this book uses

This book teaches ECMAScript 5, the current version of JavaScript that is supported by all modern engines. If you have to work with, say, older web browsers, then Chapter 25 explains what features are exclusive to ECMAScript 5.

Tips for Reading This Book

The most important tip for learning JavaScript is don’t get bogged down by the details. Yes, there are many details when it comes to the language, and this book covers most of them. But there is also a relatively simple and elegant “big picture” that I will point out to you.