Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Do not buy this book

Do not buy this book. There are so many script examples in this book that do not work, let alone there are many weak and sloppy algorithms and code logic structures the author introduced. If you already bought this book, see his script example in Chapter 13 (A Sample Authentication Implementation), try to read line by line in his Cookie class example, can you find any flaw? Well, there are many them in this tiny/simple class, but i can just ignore and pretend to think that the author did not have enough time to test his own scripts before he put them in his book...but the algorithm/logic structures of the codes that bothers me! Weak algorithm, bad code control structure can lead to a buggy application that is not easy to debug!