Opdyke, don Roberts. In the past  this book was always talked by friends and was strongly recommended to me as a primary guigude to senior software deverloper. However, for the sake of my laziness, I start to read this book until now. 

Refactoring: Imporvinmg the design of the existing code shows how refactoring can make object-oriented code simple and easier to maintain. Today refactorign require considerable design know-how, but once tools become availables, all programmers should be able to imporve their coding using refactoring techniques.

Early chapters stress the importance of testing in the successful refactoring (When you imporve code, you have to test tot verify that it still works).After the discuss on how to detect ‘smell‘ of bad code, readers get to heart of the book,it catalog of over 70 ‘refactorings‘--tips for better and simpler class design. Each tip of is illustrated with before and after code. 

【RefactoringCode】The description of the refactoring book