David Herman - Effective JavaScript: 68 Specific Ways to Harness the Power of JavaScript

68 Specific Ways to Harness the Power of JavaScript

David Herman

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ISBN-13: 978-0-321-81218-6
ISBN-10: 0-321-81218-2

Text printed in the United States by RR Donnelley in Crawfordsville, Indiana.
First printing, November 2012

Living up to the expectation of an Effective Software Development Series programming book, Effective JavaScript by Dave Herman is a must-read for anyone who wants to do serious JavaScript programming. The book provides detailed explanations of the inner workings of JavaScript, which helps readers take better advantage of the language.

Erik Arvidsson, senior software engineer

Its uncommon to have a programming language wonk who can speak in such comfortable and friendly language as David does. His walk through the syntax and semantics of JavaScript is both charming and hugely insightful; reminders of gotchas complement realistic use cases, paced at a comfortable curve. Youll find when you finish the book that youve gained a strong and comprehensive sense of mastery.

Paul Irish, developer advocate, Google Chrome

Before reading Effective JavaScript, I thought it would be just another book on how to write better JavaScript. But this book delivers that and so much moreit gives you a deep understanding of the language. And this is crucial. Without that understanding youll know absolutely nothing whatever about the language itself. Youll only know how other programmers write their code.

Read this book if you want to become a really good JavaScript developer. I, for one, wish I had it when I first started writing JavaScript.

Anton Kovalyov, developer of JSHint

If youre looking for a book that gives you formal but highly readable insights into the JavaScript language, look no further. Intermediate JavaScript developers will find a treasure trove of knowledge inside, and even highly skilled JavaScripters are almost guaranteed to learn a thing or ten. For experienced practitioners of other languages looking to dive headfirst into JavaScript, this book is a must-read for quickly getting up to speed. No matter what your background, though, author Dave Herman does a fantastic job of exploring JavaScriptits beautiful parts, its warts, and everything in between.

Rebecca Murphey, senior JavaScript developer, Bocoup

Effective JavaScript is essential reading for anyone who understands that JavaScript is no mere toy and wants to fully grasp the power it has to offer. Dave Herman brings users a deep, studied, and practical understanding of the language, guiding them through example after example to help them come to the same conclusions he has. This is not a book for those looking for shortcuts; rather, it is hard-won experience distilled into a guided tour. Its one of the few books on JavaScript that Ill recommend without hesitation.

Alex Russell, TC39 member, software engineer, Google

Rarely does anyone have the opportunity to study alongside a master in their craft. This book is just thatthe JavaScript equivalent of a time-traveling philosopher visiting fifth century BC to study with Plato.

Rick Waldron, JavaScript evangelist, Bocoup

For Lisa, my love

As is well known at this point, I created JavaScript in ten days in May 1995, under duress and conflicting management imperativesmake it look like Java, make it easy for beginners, make it control almost everything in the Netscape browser.

Apart from getting two big things right (first-class functions, object prototypes), my solution to the challenging requirements and crazy-short schedule was to make JavaScript extremely malleable from the start. I knew developers would have to patch the first few versions to fix bugs, and pioneer better approaches than what I had cobbled together in the way of built-in libraries. Where many languages restrict mutability so that, for example, built-in objects cannot be revised or extended at runtime, or standard library name bindings cannot be overridden by assignment, JavaScript allows almost complete alteration of every object.

I believe that this was a good design decision on balance. It clearly presents challenges in certain domains (e.g., safely mixing trusted and untrusted code within the browsers security boundaries). But it was critical to support so-called monkey-patching, whereby developers edited standard objects, both to work around bugs and to retrofit emulations of future functionality into old browsers (the so-called polyfill library shim, which in American English would be called spackle).

Beyond these sometimes mundane uses, JavaScripts malleability encouraged user innovation networks to form and grow along several more creative paths. Lead users created toolkit or framework libraries patterned on other languages: Prototype on Ruby, MochiKit on Python, Dojo on Java, TIBET on Smalltalk. And then the jQuery library (New Wave JavaScript), which seemed to me to be a relative late-comer when I first saw it in 2007, took the JavaScript world by storm by eschewing precedent in other languages while learning from older JavaScript libraries, instead hewing to the query and do model of the browser and simplifying it radically.

Lead users and their innovation networks thus developed a JavaScript home style, which is still being emulated and simplified in other libraries, and also folded into the modern web standardization efforts.