Customer Reviews

Sams Teach Yourself Perl in 21 Days (2nd Edition)

5 star:		(5)
4 star:		(4)
3 star:		(1)
2 star:		(0)
1 star:		(1)

 

 

Teach Yourself Perl in 21 Days by Laura Lemay is sufficient for the beginner wanting to learn Perl, be it on Windows or a UNIX-based operating system. If Perl is your first programming language, then this book is a fairly good book to choose as a starting point. It teaches the basics of programming in Perl and moves quickly from that point onward.

However, while this approach introduced me to the language I found my ability to pace through the book as I normally would with other programming languages hindered by the author's organization. Unexplained code is used in almost all of the examples before you get to its respective chapter. While this approach may work for some and give cause for thinking, it gave me an unnecessary headache.

Don't get me wrong, it did teach me a good bit about Perl, it inspired me to install Debian Linux on my programming workstation, and left me to pursue Perl. Despite this, I turned to Learning Perl. I found Lemay's writing to be too verbose and the organization of the book a bit of a twister.

Overall, it can be summed up by the following pros/cons:

~ Pros
- Good introduction to Perl
- Independent of Operating System (Great for Windows users ready to Learn Perl and perhaps Migrate to Linux for programming purposes)
- Solid examples and references
- Covers more advanced topics later on

~ Cons
- Verbose
- Awkward structure. Things such as loops are constantly used in beginning examples without much of an explanation. If you don't' have any experience with programming, it will give you a headache. The sections on these devices come much later, and have a strange introduction as well.
- Frustrating at times when it shouldn't be (IE, having you use functions that you haven't learned, or haven't been mentioned, in an example for a particular chapter)

Additionally, I'd recommend picking up Learning Perl or using it instead. I picked up Teach Yourself Perl in 21 Days, learned what I could, and then fell in love with Learning Perl's concise, straight to the point chapters and examples (albeit with a fair amount of humor). If you're a Linux/UNIX user, you'll probably find Learning Perl a better catch, but for me, Teach Yourself Perl in 21 Days was the stepping stone to Linux and Learning Perl. Overall, I'm satisfied with my purchase.

If you want to start programming Perl in the shortest time possible, and have some programming background, you will benefit from reading Sam's Teach Yourself Perl in 24 Hours, which packs a lot of practical materials and emphasizes get-your-hands-dirty-immediately as well as uses a lot of code snippets to teach.

This "in 21 days" book, on the other hand, is better if you have more time to learn Perl. Each lesson takes 1-2 hours, if you already have some programming background, and longer if you don't. This book treats Perl more systematically and in more details than the "24 hours" book. It explains a lot of concepts, including hashes and modules, more clearly than the "24 hours" book. I recommend you do 2 or 3 lessons each day, because Perl is such a compact yet complicated language, that it's best to force yourself to learn it quickly, rather than slowly, because slow learning will make you forget things. Be sure to study the examples in the book until you understand every line of code.

I bought this book after trying to learn Perl through another book (Perl for Bioinformatics). This book is definitely a better introduction to Perl than any other book I've seen. It is clear and concise enough and although it might be hard to finish it in 21 days, you can start coding your own scripts much before the end of the book. I am still on chapter 11 and I can program most of what I need with it (i.e parsers and simple bioinformatics applications). I recognize that there are a few typos on the book but if even Knuth's Art of Computer Programming have them why shouldn't Lemay's Teach Yourself Perl in 21 Days do the same?

Given what I said above, I must warn begginer programmers (like me) that Perl is not the best language for you to learn as your first one. It is a dirty scripting language which does the job and is most suitable for parsing files and formatting data but it has a lot of things which make it quite confusing initially (its context dependency for instance). If you want to learn something that will give a solid programming base you should start with something else (i.e. Java, Pascal, Ruby etc) which will probably be a little bit harder but will payoff later.

This book is not helpful for the newbies. Not only do some of the scripts not work, but the way Perl is explained in this book, it just doesn't make enough sense. I learned more from online tutorials that were perhaps 3 pages long than I learned in 15 pages of one chapter of this book. I usually pick things up quite easily, so it must be the book that is confusing.

At least two of the script examples given in Chapters 1-8 had typos in them, and not enough explanation for someone that doesn't know much to figure out what. I am unfortunately going to have to give up on this book to learn Perl and turn to the internet... too bad I spent $35 for the book. I don't recommend this book to anyone except perhaps someone that already knows Perl.

The bad:


1. It has many typos and mistakes. Mistakes in a "teach yourself" book are particularly unacceptable.

2. The explanations are very tedious to read and not very good. If you have never programmed then these tedious explanations may be of some help to you, although better quality explanations of the language are available elsewhere. But if you're an experienced programmer looking to learn Perl then reading an explanation of how a while loop works over and over again will, to say the least, not be your cup of Java. This is especially strange since, as it said in the book, this book is written for readers with at least some programming experience. Furthermore, many of the explanations are so vague that they're practically useless. For instance, instead of giving an explanation about the local scope of a foreach loop variable, the author says "if it [the iterating variable in the foreach loop] doesn't exist prior to the loop, it'll stop existing after the loop. If it does exist prior to the loop, the foreach will just use it as a temporary variable, and then restore its original value when you're done looping. You can think of the foreach variable as a sort of scratch variable used solely to store elements, which is then thrown away when the loop's done." And I consider this to be a representative example of most of the explanations in this book.

3. This book is a bad reference. Many people buy programming books so that they can quickly read a few pages and learn some detail about some language feature. For this, the book is useless. There are many features that do NOT have a full explanation, only a partial one, and even these are often times strewn around the book so that you'll have to search for them. And personally, I can not use this book as a reference since I have doubts about the correctness of many of its explanations.

4. The author will MANY times give a vague description of a feature and then tell you to look at the Perl documentation for more details. This makes the book useless for a beginner (since they're just learning the language) and useless for someone who already knows the language and is using it as a reference (since then they may as well have just gone to the Perl documentation from the outset).

5. The example programs are not that well written. The quality of the example programs reminds me of something that I would have written when I had just a few years of programming experience.

6. The book tells you many times about what you're going to learn about later in the book, which gets annoying.

7. The author includes useless programming examples for some reason. Ex: "For example, here's a somewhat pointless for loop that creates an array, and then destroys it, backwards, printing the number of remaining (sic) and the array itself as it goes: [shows the code] I can't image what sort of Perl program would need this kind of loop, and because it iterates over a list it would probably make more sense as a foreach."

8. Mistakes such as not knowing when to use "that" or "which" are unacceptable for any author.



The good:


1. If you're a beginner and if you can stand reading through all of it then you will learn something about the Perl language and you will learn how to create a quick script (although as a word of caution, if you emulate this book's examples then your scripts likely won't be very good).



This programming book is among the worst that I have seen.
Overall, I wish that I had bought another book.

I am currently using this book as a companion for my Perl/CGI course. It is an excellant book. When I have problems understanding what the professor talks about in class, I just come home and go over the similar topics in the book. If you are a student planning on taking a Perl/CGI course, you should purchase this book.

Not a bad way to start off learning Perl. This provides a good foundation to learn it in more detail. Keep up the great work!

A basic, but well written book. I have only gotten to the 3rd chapter but satisfied with this purchase. I also use the net for additional information.

This isn't bad. I think it moves kinda fast, but that may just be me. This is seriously the only presentation of the subject matter that I'd consider reading to completion. This is a good introduction to Perl and a good reference for the future.

I find myself using this book as a refernce almost every day. It is well written and easy to follow. I highly recommend it.