Customer Reviews

Learning JavaScript, 2nd Edition

5 star:		(3)
4 star:		(3)
3 star:		(3)
2 star:		(1)
1 star:		(2)

 

 

I recently became the maintainer for a site that uses a bit of JavaScript. Surprisingly, I have no previous experience writing or maintaining anything in JavaScript, so I needed to get up to speed, if only to know what is going on. To help me out, I picked up a copy of Shelley Powers' new book, Learning JavaScript.

I am familiar with Shelley Powers' work, having read Unix Power Tools, a book that holds a special place on my shelf for its usefulness and depth. She is obviously someone who knows what she is doing.

This book states in the preface that, "Readers of this book should be familiar with web page technology, including Cascading Style Sheets (CSS) and HTML/XHTML. Previous programming experience isn't required, though some sections may require extra review if you have no previous exposure to programming."

That sums up the only negative thing I might be tempted to say about the book. Usually, O'Reilly's "Learning" series books are excellent resources for complete newcomers and are the sort of books that I might point a novice toward. While this book is designed for the JavaScript novice, it is not the best resource for a programming/web creation novice. If you can't follow or understand the following quoted sentences, this book isn't for you. If you can, this book does an excellent job of covering the basics of JavaScript in depth and may end up being the only text you need on the topic.

"JavaScript has just three primitive data types: string, numeric, and boolean. Each is differentiated from the others by the type of value it contains: string, numeric, and boolean, respectively."

My first exposure to programming was in 1981, using BASIC on a Radio Shack TRS-80 Color Computer. Over the years, I have studied (and often forgotten, but can certainly read a bit and understand the concepts of) LISP, C, Bash scripting, Perl, Python, and more. Lately I have spent more time using PHP and enjoying it, since that is the language of things like Wordpress, Drupal, vBulletin and other commonly used CMS and interactive web site software. The two sentences quoted above seem perfectly clear to me, but I can imagine what they must seem like to someone with no experience with programming languages. So, now you have been warned. Let's get to the good stuff for those who understand the jargon.

This book is clear, with enough detail to help you understand what is happening without bogging you down in the minutiae. The reader is expected to see how and why each facet of the language would be useful, so the examples given are simple and seem to be designed to help the reader get the feel for usage without pretending to be a cookbook of programming recipes, although some seem quite useful as they are, such as Chapter 6's code for browser detection, which allows you to modify content and/or how it is displayed based on the web browser being used to view your site.

The text covers everything you are likely to need while using JavaScript, and more importantly for me, most everything a person is likely to stumble across when reading existing code. You get a solid introduction to data types and variables, operators, statements, objects, and functions. This is built upon with chapters on debugging and cross-browser compatibility. This new second edition (just released earlier in 2009) has several updates and changes from the previous version including a wonderful comparison of the benefits of generating and processing XML data using Ajax versus using JSON.

If you are considering using JavaScript on a website that includes the dynamic creation of web pages, or if you have inherited one that you are now responsible for maintaining, this book would be a good resource to help you start to understand one of the more common languages used for doing so. This is especially true if you have any prior experience with any other programming language. If you want a cookbook, scripted-style, "do this, now do that" sort of beginner's guide to making a site that holds your hand through the whole process, this is not the book you want.

I have to concur that while this book is marketed as a book for newcomers to javascript, it is too full of unexplained terminology for the beginner. I am very familiar with HTML and CSS, and the introduction to this book claims that should have been good enough for a starting point, but here I am scratching my head about every third sentence and having to run to the web for clarification.

Other "beginning" O'Reilly books I have used relied on a tutorial model that starts with a "hello world" example and builds upon it to introduce more complicated concepts. Powers' book does indeed start with a "hello world" example, but does not build upon it. Instead, each chapter focuses on a particular facet and provides isolated examples that are not connected back to previous examples. It is arranged more like a basic reference text than a learning tool.

I am trudging through this book right now, and as a beginner who has no prior experience with JavaScript, I can tell you that this book isn't for the beginner. I've gone through a few examples and typed in the code as written and found that a few of the examples don't even work. I'm sure that it was written using some sort of word processing software, so what made it so hard to copy and paste the JavaScript code into a file to check to see if the code actually works? Also, I don't understand why the examples are so complex. After reading and rereading the script examples, I can usually figure it out, but having to do that is why I say that this book is not for the beginner.

The good part about this book, is that I am actually learning the material. The "test" questions at the end of the chapter range from simple to intermediate, and I can answer all of them correctly. I just wish it was a bit easier to read for us beginners.

While the author clearly knows what she's talking about, the way the information is presented in this book, it's very difficult to follow at times unless you are an experienced programmer. It reads less like a friendly instructor bending over your shoulder guiding you along, and more as someone standing at a podium reading from an encyclopedia using incredibly distilled language that gets quite tedious after a while. As others have already pointed this out, I thought I would include some specific examples to illustrate.

Here is a sample of text from Chapter 7:
"The XHTML transitional and strict DOCTYPEs trigger standards mode for most browsers, depending on whether the page is served up as XHTML with an optional XML prolog."

I had to read this several times to first find the verb. At no time is 'transitional' defined, nor is the concept of 'XML prolog'. It's mentioned once here and then dropped. Head swimming. I want to roll up this sentence and toss it back.

There are several examples that mention (as opposed to formally introduce) concepts that haven't been spoken about yet. This is quite jarring for a reader trying to follow along. Again, as an example in Chapter 7, there is lots of discussion around accessing the DOM objects using JavaScript, but none of this has actually been covered yet.

Not to belabor the point, but there was one needlessly complicated example (5-5) to illustrate embedded functions where a function is called from within a return statement from inside a function inside another function. This makes my head want to explode. I wish the author spent at least a paragraph trying to explain exactly how this would work, because it's not at all clear.

I will update the review as I follow along, but for now yes I'm learning JavaScript, but aaarrrgh!

I've read a few reviews here stating that this book isn't for the beginning programmer or the non-programmer. Well I'm an experienced programmer and the book is not worthwhile to me.

As a programmer, I'm looking for useful explanations of the core features of a language. For instance, JavaScript has two special types "null" and "undefined." That's unusual and I assume there is a reason for this. Maybe it helps avoid errors. Or maybe it was just a mistake in design. I lean towards the former. Anyway... the description in this book didn't touch on *why* there are null and undefined types. It "explained" them in a hurry and was so convoluted I'm more confused than if I hadn't looked at this book! And that's just one example.

The title is "Learning Javascript" which is a general-purpose scripting language with its roots in the web. However, this book is very geared towards examples stuck in HTML. I think the title should have made it clear that this was web-oriented.

I don't expect to finish this book. I'd like to trust O'Reilly as being the authority in teaching technical tools, but this is the 3rd time I've been very disappointed. (MySQL for instance).

Some reviewers felt it wasn't appropriate for beginners. I think the book is targeted for people who have some programming experience, but you don't need ANY Javascript background to find this book immensely helpful. A basic understanding of HTML I think is a must. Beyond that, you could learn Javascript with very little understanding of programming.
Shelley meticulously steps through the language and applications. Though occasionally using something discussed later in the book, she tells you so and where she will discuss it further; I didn't find those few references to be a problem.
Shelley provides real examples every step of the way. Whenever I think she may have made a mistake (and I take pen in hand to tell her so), I find I just didn't read carefully.
Shelley nicely handles the cross-browser issues as well though AFTER reading this book, you may want to think about JQuery as a next step.

If you are an experienced programmer looking to add JavaScript to your repertoire this book is completely useless with the exception of chapter 13 which covers the very basics of "Custom JavaScript Objects". I can not find a good way way to express my sheer astonishment at someone putting custom and object in the same sentence never mind a chapter title. I pulled this off the shelf, not sure when it got there, to refresh myself on JavaScript objects for work I am doing in NodeJS. I ended up retrieving my copy of "JavaScript: The Definitive Guide: Activate Your Web Pages (Definitive Guides) by David Flanagan" from a co-worker. I recommend the Flanagan book as well as "JavaScript: The Good Parts by Douglas Crockford" as a pair to anyone trying to learn the language. More advanced persons may be interested in "JavaScript Patterns by Stoyan Stefanov" as well.

50% of this book goes over basic programming concepts like the basics of primitive types, how to create loops and 'if else' forests (hint: there just like every other weakly typed language). This in and of its self is not a deal breaker for me, it is always good to make sure there are no huge syntactical differences in the language. The fact that the most advanced language aspects that the author goes over are built in object wrappers for primitives, and the basics of functions is however. The functions chapter does have 2 pages on 'Anonymous Functions' and another 3 pages on 'Nested Functions' which are rather unique to JavaScript (or OZ if anyone else is unlucky enough to have experience there). Most of the rest of the book Deals with the DOM, and DHTML techniques (Note to novices: These techniques have been deprecated for a decade). The last two chapters cover AJAX and the differences in JSON and XML. If you do not have experience with those, buy a book expressly on those topics, this is an expansive topic... hence why there are whole books on it.
In conclusion, this is the first book that I have ever actually thrown away, I could not even bring myself to give it away.

I understand that there is a newer edition, but this one is still worth the money. Amazona and eBay are good sources for the right price. And, the prices are for new copies. So buy it and save some money over the newer one. Can't see many changes omitted in this one. It covers Ajax and DOM!

I suppose if you are reading this book and have no prior knowledge of JavaScript, then you might think it is a good book with a wide range of coverage. But, as an instructor that teaches JavaScrip and used this book as courseware, I can tell you that this book is horrible. There errors in the code samples are in the DOZENS and the ommision of important material and thin coverage of otehrs makes this book a waste of time and money when "JavaScript: The Definitive Guide" is out there.

This is a solid book, probably the best introduction to Javascript I've seen. If you are new to Javascript, start here and also check out DOM Scripting: Web Design with JavaScript and the Document Object Model as a companion piece.

Some sections could use a little more explanation, however, particularly with closures and exception handling.