You Don't Know JS: Up & Going

Preface

I’m sure you noticed, but “JS” in the series title is not an abbreviation for words used to curse about JavaScript, though cursing at the language’s quirks is something we can probably all identify with!

From the earliest days of the Web, JavaScript has been a foundational technology that drives interactive experience around the content we consume. While flickering mouse trails and annoying pop-up prompts may be where JavaScript started, nearly two decades later, the technology and capability of JavaScript has grown many orders of magnitude, and few doubt its importance at the heart of the world’s most widely available software platform: the Web.

But as a language, it has perpetually been a target for a great deal of criticism, owing partly to its heritage but even more to its design philosophy. Even the name evokes, as Brendan Eich once put it, “dumb kid brother” status next to its more mature older brother, Java. But the name is merely an accident of politics and marketing. The two languages are vastly different in many important ways. “JavaScript” is as related to “Java” as “Carnival” is to “Car.”

Because JavaScript borrows concepts and syntax idioms from several languages, including proud C-style procedural roots as well as subtle, less obvious Scheme/Lisp-style functional roots, it is exceedingly approachable to a broad audience of developers, even those with little to no programming experience. The “Hello World” of JavaScript is ...