Refactoring: Improving the Design of Existing Code, 1e  (Paperback, Fowlar)

Apart from refactoring, one also learns how to write quality code. The step by step approach of cleaning up your code without breaking the current functionality helps a lot. For e.g. approach to breaking long classes/methods into smaller ones is excellent. This book describes how we can extract classes out of a various big classes based on various responsibilities which then can be reused by other classes. It describes ways we can simplify complicated/nested if/else conditional blocks, switch...