You Don't Know JS: ES6 & Beyond

Foreword

Kyle Simpson is a thorough pragmatist.

I can’t think of higher praise than this. To me, these are two of the most important qualities that a software developer must have. That’s right: must, not should. Kyle’s keen ability to tease apart layers of the JavaScript programming language and present them in understandable and meaningful portions is second to none.

ES6 & Beyond will be familiar to readers of the You Don’t Know JS series: they can expect to be deeply immersed in everything from the obvious, to the very subtle—revealing semantics that were either taken for granted or never even considered. Until now, the You Don’t Know JS book series has covered material that has at least some degree of familiarity to its readers. They have either seen or heard about the subject matter; they may even have experience with it. This volume covers material that only a very small portion of the JavaScript developer community has been exposed to: the evolutionary changes to the language introduced in the ECMAScript 2015 Language Specification.

Over the last couple years, I’ve witnessed Kyle’s tireless efforts to familiarize himself with this material to a level of expertise that is rivaled by only a handful of his professional peers. That’s quite a feat, considering that at the time of this writing, the language specification document hasn’t been formally published! But what I’ve said is true, and I’ve read every word that Kyle’s written for this book. I’ve followed every change, and ...