Clean Code: A Handbook of Agile Software Craftsmanship

Even bad code can function. But if code isn't clean, it can bring a development organization to its knees. Every year, countless hours and significant resources are lost because of poorly written code. But it doesn't have to be that way.

Noted software expert Robert C. Martin, presents a revolutionary paradigm with Clean Code: A Handbook of Agile Software Craftsmanship . Martin, who has helped bring agile principles from a practitioner's point of view to tens of thousands of programmers, has teamed up with his colleagues from Object Mentor to distill their best agile practice of cleaning code on the fly into a book that will instill within you the values of software craftsman, and make you a better programmerbut only if you work at it.

What kind of work will you be doing? You'll be reading codelots of code. And you will be challenged to think about what's right about that code, and what's wrong with it. More importantly you will be challenged to reassess your professional values and your commitment to your craft.

Clean Code is divided into three parts. The first describes the principles, patterns, and practices of writing clean code. The second part consists of several case studies of increasing complexity. Each case study is an exercise in cleaning up codeof transforming a code base that has some problems into one that is sound and efficient. The third part is the payoff: a single chapter containing a list of heuristics and smells gathered while creating the case studies. The result is a knowledge base that describes the way we think when we write, read, and clean code.

Readers will come away from this book understanding

• How to tell the difference between good and bad code
• How to write good code and how to transform bad code into good code
• How to create good names, good functions, good objects, and good classes
• How to format code for maximum readability
• How to implement complete error handling without obscuring code logic
• How to unit test and practice test-driven development

• What smells and heuristics can help you identify bad code This book is a must for any developer, software engineer, project manager, team lead, or systems analyst with an interest in producing better code.

  Autorentext
  Robert C. “Uncle Bob” Martin has been a software professional since 1970 and an international software consultant since 1990. He is founder and president of Object Mentor, Inc., a team of experienced consultants who mentor their clients worldwide in the fields of C++, Java, C#, Ruby, OO, Design Patterns, UML, Agile Methodologies, and eXtreme programming.

  Klappentext

  Anyone with a modicum of industry experience knows that there is an awful lot

of bad code out there. It's not that it's just unsightly. Code that is not clean can

quite easily move beyond being a functional problem to becoming an expensive

organizational issue that has to be dealt with immediately.

There are no shortage of suggestions and methods for cleaning up your code

after it has been written, but in this new book, Robert C. Martin espouses

nipping these potential problems in the bud by cleaning on the fly, rather than

doing it in segments or waiting until the end of a project. The book is a tutorial

and reference that will teach the reader to conceive and write cleaner code

through a multitude of proven examples.

This book shows the PROCESS of cleaning code. Rather than just illustrating

the end result, or just the starting and ending state, Martin shows how several

dozen seemingly small code changes can positively impact the performance and

maintainability of an application's code base. It will also explain why each of

those changes was made. In the end the book will boil all these changes down

into a suite of heuristics and principles that will guide the reader in his own

code cleanups.

Zusammenfassung

Even bad code can function. But if code isn’t clean, it can bring a development organization to its knees. Every year, countless hours and significant resources are lost because of poorly written code. But it doesn’t have to be that way.

Noted software expert Robert C. Martin presents a revolutionary paradigm with Clean Code: A Handbook of Agile Software Craftsmanship. Martin has teamed up with his colleagues from Object Mentor to distill their best agile practice of cleaning code “on the fly” into a book that will instill within you the values of a software craftsman and make you a better programmer—but only if you work at it.

What kind of work will you be doing? You’ll be reading code—lots of code. And you will be challenged to think about what’s right about that code, and what’s wrong with it. More importantly, you will be challenged to reassess your professional values and your commitment to your craft.

Clean Code is divided into three parts. The first describes the principles, patterns, and practices of writing clean code. The second part consists of several case studies of increasing complexity. Each case study is an exercise in cleaning up code—of transforming a code base that has some problems into one that is sound and efficient. The third part is the payoff: a single chapter containing a list of heuristics and “smells” gathered while creating the case studies. The result is a knowledge base that describes the way we think when we write, read, and clean code.

Readers will come away from this book understanding

• How to tell the difference between good and bad code
• How to write good code and how to transform bad code into good code
• How to create good names, good functions, good objects, and good classes
• How to format code for maximum readability
• How to implement complete error handling without obscuring code logic

• How to unit test and practice test-driven developmentThis book is a must for any developer, software engineer, project manager, team lead, or systems analyst with an interest in producing better code.

  Inhalt
  Foreword xix
  Introduction xxv
  On the Cover xxix

  Chapter 1: Clean Code 1
  There Will Be Code 2
  Bad Code 3
  The Total Cost of Owning a Mess 4
  Schools of Thought 12
  We Are Authors 13
  The Boy Scout Rule 14
  Prequel and Principles 15
  Conclusion 15
  Bibliography 15

  Chapter 2: Meaningful Names 17
  Introduction 17
  Use Intention-Revealing Names 18
  Avoid Disinformation 19
  Make Meaningful Distinctions 20
  Use Pronounceable Names 21
  Use Searchable Names 22
  Avoid Encodings 23
  Avoid Mental Mapping 25
  Class Names 25
  Method Names 25
  Don't Be Cute 26
  Pick One Word per Concept 26
  Don't Pun 26
  Use Solution Domain Names 27
  Use Problem Domain Names 27
  Add Meaningful Context 27
  Don't Add Gratuitous Context 29
  Final Words 30

  Chapter 3: Functions 31
  Small! 34
  Do One Thing 35
  One Level of Abstraction per Function 36
  Switch Statements 37
  Use Descriptive Names 39
  Function Arguments 40
  Have No Side Effects 44
  Command Query Separation 45
  Prefer Exceptions to Returning Error Codes 46
  Don't Repeat Yourself 48
  Structured Programming 48
  How Do You Write Functions Like This? 49
  Conclusion 49
  SetupTeardownIncluder 50
  Bibliography 52

  Chapter 4: Comments 53
  Comments Do Not Make Up for Bad Code 55
  Explain Yourself in Code 55
  Good Comments 55
  Bad Comments 59
  Bibliography 74

  Chapter 5: Formatting 75
  The Purpose of Formatting 76
  Vertical Formatting 76
  Horizontal Formatting 85
  Team Rules 90
  Uncle Bob's Formatting Rules 90
  Chapter 6: Objects and Data Structures 93
  Data Abstraction 93
  Data/Object Anti-Sy…