Practical Modern JavaScript

Foreword

When I created JavaScript in 1995 at Netscape, I had no definite idea that it would become the most widely used programming language on the Internet. I did know that I had very little time to get it into “minimum viable shipping” state, and so I made it extensible and mutable from global object on down, even to base-level meta-object protocol hooks (e.g., toString and valueOf, styled after Java’s methods of the same names).

Yet in spite of its ongoing evolution and still-rising popularity, JavaScript always benefits from an incremental and careful teaching approach that puts first things first. I think this follows inevitably from the hurried design and intentional extensibility. I overloaded two kernel elements, functions and objects, so that programmers could use them in various ways as general workalikes for individual tools in a larger Swiss army knife. This meant that students would need to learn which tool was best to use for a specific task, and how precisely to wield that particular blade.

Netscape was a whirlwind for me, and I think for anyone there from early 1995 on. It was rushing toward an initial public offering predicated on competing with Microsoft via the infamous “Netscape + Java kills Windows” formula repeated by Marc Andreessen on the IPO roadshow that year. Java was the big-brother or “Batman” programming language to little-brother, “Robin the boy hostage” sidekick “scripting language,” JavaScript.

But I knew while I was writing the first version ...