JavaScript: The Good Parts: The Good Parts

Do you struggle when creating objects in Javascript?Do you find the syntax to be non-intuitive and frustrating?Do you know the difference between using a function as an object vs using an object literal?Do you know how using object literals can simplify your code and create something similar to namespaces?Do you know how to augment the type system -- for example, if wanted all strings to have a trim() method?Do you know why the "new" statement is so dangerous? Do you know an alternative that eliminates the use of "new" entirely?These are some of the topics that the book touches upon.This book is aimed at someone with intermediate programming experience that wants to know the best way to create and use objects, arrays, types, etc. Crockford takes his experience with Javascript to show you best practices coding techniques and styles to use with Javascript. In addition, the book provides insights into what makes Javascript so confusing and what can be done about it.You might ask "Isn't this stuff already covered in other books that I have?" The answer is no. For one, most other books use a psuedo-classical coding style (see below) to explain objects that is a source of confusion.Javascript can be very confusing, especially for programmers who have extensive experience in other C-based languages (like myself). Writing good Javascript that uses objects, methods, etc. is hard. In Javascript, if you want to create objects, use inheritance and create methods, you have several different ways to write your code and it's difficult to know what the strengths and weaknesses of each are.Crockford explains the problem plainly. Other C-based languages use class inheritance (Crockford calls this classical inheritance). Javascript, on the other hand, is the only popular language that uses prototype inheritance, which does not have classes. However, the syntax which Javascript uses to create object is Java-like (Crockford calls this pseudo-classical syntax). It's confusing, because it keeps you in a class-based frame of mind while working in a language that has no concept of classes.Clarifying what's going on with the object model is the best part of this book. Crockford also explains other parts of Javascript that can be problematic and the techniques that he prefers for handling them. I don't necessarily agree with all of them, but the important thing is that he explains his reasoning.To effectively learn Javascript, I recommend that you buy 1) a book that covers the details of the language and can be used as a reference (e.g. Javascript, the Definitive Guide) and 2) Crockford's book. Advanced programmers might also enjoy Pro Javascript Design Patterns, which shows a number of ways to combine Javascript with some of the GoF patterns. I would avoid any cookbook style books on Javascript, because you're better off using YUI, JQuery or one of the other Javascript libraries than writing your own drag-and-drops, calendars, etc.There are a series of Yahoo! videos by Crockford that mirror the material in this book and can be found as podcasts under YUI Theater. They contain nearly all of the material in the book and probably a little more. Those videos are:- Douglas Crockford/An Inconvenient API: The Theory of the DOM (3 parts)- Douglas Crockford/The JavaScript Programming Language (4 parts)- Douglas Crockford/Advanced JavaScript (3 parts)- Douglas Crockford/Javascript The Good Parts

I just finished this book. It's relatively short but you have to invest a lot of hours to properly absorb it. I think I'm going to need one more pass.I do not understand the majority of complaints. Some compare Crockford to "the most boring professor you ever had", others said the information was poorly organized and not written very well. Others complained about his ego getting in the way. I, for one, found it to be very interesting and useful. Parts of it were a struggle to get through (and I've been a C coder for 20+ years) but mental challenges are a software engineer's specialty.In my opinion, none of the complaints are completely true, assuming you are the right audience. This book is NOT for beginners. If you are relatively new to Javascript, it will definitely be useful, but if you are new to programming entirely, this book is not for you. This is a more academic book that gives you a peek behind the scenes to the inner workings of the Javascript language. It is more comparable to K&R's book for C Programmers, but not as complete (just the "good" and "awful" parts!).It is a book about the Javascript LANGUAGE. It is NOT a book on web programming. It will NOT teach you anything about HTML, or the DOM, or how to put little fiddlly-bits on the screen, or how to work out game physics, or how to use any HTML-specific components. It is a book on the constructs of Javascript, plain and simple. It should NEVER be the only book on Javascript you would own, but if you are serious about Javascript, it should definitely be in your library. I don't think you can be a Javascript master without this book.My minor grievances are mostly limited to subjective areas where I disagree with him:1) He states his opinion absolutely, more so in the first part of the book. I prefer a less forceful approach that presents the arguments and lets you decide for yourself. However, I do not feel he went overboard in this regard as some did - I suspect they didn't get very far into the book.2) While I completely understand the Javascript bugaboo that makes a case for mis-aligned curly braces (K&R style). I cannot get myself to follow this convention (except in a few areas where I make exceptions) To me, code is SO much easier to follow when all blocks are aligned. I will heed his advice and avoid the lurking JS bug, but I will not fully convert to misaligned braces. I resent that his JSLint tool generates hundreds of errors in my code because of this - but fortunately, there's an option to turn it off.3) When he digs into some of the JS-specific patterns that aren't familiar to non-JS programmers, I wish he would add a disclaimer along the lines of "while this is a powerful tool, understand that depending on such patterns may make the code more difficult to maintain by others less trained in the specifics of Javascript. Or at least comment vigorously." I am a firm believer in "clarity over cleverness" in shared code.4) In some of the trickier subjects, a few more examples would makes things easier to comprehend. I've never really used Regular Expressions before, and the chapter left my head swimming, and I felt the explanation of the various components of the expressions could have been better.But these are not major grievances, and I whole-heartily recommend this book for the intermediate Javascript user or the novice JS user who has a solid background in general programming language constructs.