"Clean Code" by Robert C. MartinJuly 22, 2013 8:13 Comments 
We can all agree that some code is better than others. But if you write code that compiles and meets all the user's requirements, is it possible to improve this code?
Robert C. Martin's answer is an emphatic "Yes". Although sloppy code can meet short-term requirements, it quickly becomes difficult to maintain. Clean Code, Martin argues, is easier to read, understand, and test; and safer to change. Our goal should be to write Clean Code.
Robert's C. Martin (sometimes affectionately referred to as "Uncle Bob") has compiled some guidance on writing clean code into a book with the self-describing title "Clean Code".
Martin did not write the entire book- he enlisted other software developers active in the Software Craftsmanship movement to contribute. Tim Ottinger, Michael Feathers, James Gremming, Jeff Langr, Kevin Wampler, and Brett Schuchert each contributed at least one chapter, outlining a specific idea of Clean Code.
Among the key concepts: Keep classes and methods small and narrowly focused, give meaningful names to variables; don't use comments as a replacement for difficult to read code; and avoid output parameters and an excessive number of parameters.
He follows up advice on craftsmanship with a set of case studies in which he describes the refactoring of existing code bases.
Although most of the examples are in Java and I am primarily a .NET developer, I found this book very useful and applicable to any language - particularly an object-oriented language, such as C#.
Code Complete was a good book for me to read when I did. I am in the process of refactoring some code that is very difficult to maintain. I knew that it is not clean, but found myself unable to articulate exactly why.
The book is not for beginners. You should have a solid understanding of your language and of OOP concepts before tackling it. But it provides excellent guidance on writing readable, maintainable and testable code.