This document discusses principles and best practices for writing clean code, including SOLID principles, readability, testability, and maintainability. It emphasizes that readable code is understandable code with descriptive naming and avoiding confusion. Testable code focuses on isolation, decoupling, and separation of concerns. Maintainable code is easy to extend and understand with good test coverage. The document provides examples of good and bad code and recommends fighting code smells and anti-patterns.

1. CLEAN CODE
SIRAR SALIH
.NET CONSULTANT

2. In theory, it’s about...
SOLID
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3. In theory, it’s about...
S ingle responsibility principle
O pen/closed principle
L iskov substitution principle
I nterface segragation principle
D ependency inversion principle
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4. In practice, it’s all about... RTM
Readability
Testability
Maintainability
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5. Readable Code
«Programming is the art of telling another human what
one wants the computer to do.» - Donald Knuth
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6. Readable Code
«Programming is the art of telling another human what
one wants the computer to do.» - Donald Knuth
From http://www.osnews.com
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7. Readable Code
«Programming is the art of telling another human what
one wants the computer to do.» - Donald Knuth
From Pluralsight
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8. Readable Code
• Readable code is understandable code
• Naming
 Class names
 Context specific
 Method names
 Say exactly what they do
• The don’ts
 Don’t confuse
 Don’t hide
 Don’t joke
 Don’t be informal
• Tell a story!
«Programming is the art of telling another human what
one wants the computer to do.» - Donald Knuth
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9. Readable Code
Bad
«Programming is the art of telling another human what
one wants the computer to do.» - Donald Knuth
Better
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10. Testable Code
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Making it testable, is making it clean
Isolation
Decoupling
Separation of concerns
TDD
Design
Clean is the side effect of testable
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11. Testable Code
«You know you should be unit testing, so
why aren’t you doing it?» - Roy Osherove
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12. Testable Code
Bad
Good
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13. Maintainable Code
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14. Maintainable Code
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Easy to extend
A change requires one change, not ten
Easy to understand
Unbrittle
Test coverage
Spreads optimism
Importance level: Readable > maintainable
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15. Bad Code
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16. Good Code
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17. The Evil Cycle
From http://blog.codeclimate.com/
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18. Be an Agent of Change
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19. Fight Code Smells and Anti-Patterns
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Comments
Duplication
Global objects
Magic numbers
Circular dependency
Coupling
Nesting
Dead code
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20. Make it Routine
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21. Recommended Books
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22. Thank you  / Questions
Blog: http://sirars.com/
• sirar.salih@itera.no / sirars@gmail.com
• @SirarSalih