If you’re an intermediate JavaScripter who’s tired of weighty tomes and arcane examples, You Don’t Know JS – Scope & Closures by Kyle Simpson is right up your alley. This smart book takes a laser-focused look at scope and closures in JavaScript.
My rating: 5/5
Who it’s for: Intermediate JavaScripters. If you’ve heard of scope, closures, JS compiling theory, but aren’t sure you really understand them as well as you should, then this book is for you.
Review
Let me preface this review by saying I’m not a big fan of coding books.
I have been frustrated by out-of-date books, untested code, and overly complex explanations from coding wizards who have long since forgotten what it’s like to be a newbie. I’ve always been more of an in-the-trenches doer than an ivory tower studier, anyway.
So, I wasn’t expecting to like Kyle Simpson’s You Don’t Know JS: Scope & Closures book so much. A programmer friend insisted I read it, and 87 pages of golden JS secrets and epiphanies later, I’m glad I did.
This book is…
- Brief. No long-winded explanations or storytelling.
- Focused. One topic, explored deeply FTW.
- Short examples, usually just a handful of lines total.
- Easy-to-follow examples with good style choices, such as verbose variable names and comments listing the expected result.
- Concepts are explained and re-explained before moving on. This is complicated stuff for us intermediate JavaScripters, and he takes the time to attack topics from multiple angles.
Highlights
You Don’t Know JS – Scope & Closures covers:
- variables: declaring, setting, and updating
- scope
- lexing
- hoisting
- closures
- how the JavaScript compiler reads code
- tokenizing
This book deserves credit for explaining the compiler’s process of operations in a way that actually clicked for me.
I also loved the short examples. They were easy to follow, none of that 30+ lines of code spread across two pages stuff you see in other books.
The book’s small size is a plus. I took it with me on a day trip – hooray for books that aren’t the size of my laptop.
Criticisms?
The only thing I might say is that some examples in the book are like, “Yeah, duh, don’t do it that way” but to be honest, I probably had to be told some of these “duh” things myself when I was starting out a few years ago.
Overall, I’d give this book an A+. It fits into the vast gulf between “total n00b” and “JavaScript Jedi”.
Check it out on Amazon.com for the current price (as well as any coupons and deals that might be running).
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