Awesome book on how objects work in JavaScript, a very dense material, but clearly written and not hard to understand if you take your time and reread/re-examine the code samples when concepts get hairy. The book goes over constructors, prototypes, inheritance, bridging the gap between traditional methods of OOD and JavaScript. For anyone coming in with a traditional class based understanding - I suspect this book would be perfect for filling the gaps.This is not a book for complete beginners, but I think works as a wonderful intermediate book about JavaScript objects. The book is very analytical and straightforward in its methodology of explanation. The content builds on itself very logically from chapter to chapter along with clear explanations and wonderfully annotated code examples. Much of the content is framed in a way of emulating Classical behavior from other languages in JavaScript (which uses prototypal inheritance rather than classes). The final chapter is particularly good (though only 14 pages), as it FINALLY emerges from the "nuts and bolts" of OOD in JS and gives you some examples and use-cases for actually utilizing what you've been learning in all of the previous chapters. The Module Pattern of object creation and the explanation and rationale behind using closures finally makes sense to me, after being somewhat opaque in the past.