The immortal classics of software development, vividly explain the principle of refactoring and specific practices, add a lot of refactoring methods, so that you can feed with time, rich vocabulary and background notes, to help you easily read the classics. [1] Reconstruction, in a nutshell, is to improve the code in an orderly man ner without changing the behavior of the outside world. Over the years, it was the original edition of the book that made the refactoring finally come out of the small circle of programming masters and became an indispensable part of the daily development work of many ordinary programmers. The book has thus become a classic with the same name as "Design Patterns". It has been translated into Chinese, German, Russian, Japanese and many other languages, and it has been selling well all over the world. Today, whether it's refactoring itself, the industry's understanding of refactoring, or the support of development tools for refactoring, is not the same as when the book was first published. The English annotated version expands the original book according to the book website maintained by the original author Martin Fowler, adding a lot of new refactorings, making this immortal classic lasting. ner without changing the behavior of the outside world. Over the years, it was the original edition of the book that made the refactoring finally come out of the small circle of programming masters and became an indispensable part of the daily development work of many ordinary programmers. The book has thus become a classic with the same name as "Design Patterns". It has been translated into Chinese, German, Russian, Japanese and many other languages, and it has been selling well all over the world. Today, whether it's refactoring itself, the industry's understanding of refactoring, or the support of development tools for refactoring, is not the same as when the book was first published. The English annotated version expands the original book according to the book website maintained by the original author Martin Fowler, adding a lot of new refactorings, making this immortal classic lasting.