After reading just 40 pages, i can tell this is one of the best book on regular expression out there. Each page is pretty informative and author tried to give all practical examples. Each topic contains 1 or more examples which helps to understand the concept very easily.

Flow of language is excellent
Examples are accurate
Starts a topic from easy example and takes reader to details gradually
Contains regex syntax of different languages i.e. Dot Net/java
Flipkart delivery and packaging was very good

My doubts were certainly cleared. Incredibly detailed book. This book certainly belongs to my best ever CS books.

Not only does this book teach on how to learn Regex, it also goes a level deeper on why you should learn and provides a very practical approach. Reading this book was like a novel to me. I would highly recommend this for programmers with any background.