This document discusses principles of clean code from the book Clean Code. It covers naming conventions, designing methods to do one thing, code formatting with proper spacing and line lengths, and using comments effectively. Specific examples are provided to illustrate good and bad practices for naming variables and methods, using exceptions over control flow, adding vertical space between concepts, and avoiding noise comments.

1. Clean Code

2. *all examples were taken from this book
*

3. • Naming
• Designing methods
• Code formatting
• Commenting code
Let’s talk about…

4. Naming

5. Intention-revealing names
Bad
int d; // elapsed time in days
Good
int elapsedTimeInDays;
Good

6. Avoid disinformation
Bad
int a = l;
if ( O == l )
a=O1;
else
l=01;

7. Don’t use noise words (1)
Bad
getActiveAccount();
getActiveAccounts();
getActiveAccountInfo();

8. Use nouns when naming classes
Bad
class Manager { … }
class Processor { … }
class Provider { … }
GoodGood
class UserManager { … }
class PaymentProcessor { … }
class LogParser { … }

9. Use verbs when naming methods
Bad
public int sum(){ … }
public void valid() { … }
private void value() { … }
GoodGood
public int calculateSum() { … }
public boolean isValid() { … }
private setValue() { … }

10. Designing
functions/methods

11. Bad
Do one thing at a time
…
if (isTestPage(pageData))
include(pageData, isSuite);
return pageData.getHtml();
…

12. Bad
Use exceptions over control flow (1)

13. Good
Use exceptions over control flow (2)

14. Code formatting

15. Vertical space between concepts (1)
Bad

16. Good
Vertical space between concepts (2)

17. Optimal line length
• Python: <79
• Java: <80
• C++ (Google, GCC): <80
• Javascript: <80
• PHP: 75-85, <120

18. Use clear naming instead of comments
Bad
GoodGood

19. Good
Informative comments

20. Do you really need TODOs?

21. Javadoc for each function?
Bad

22. Noise comments

23. Comments are dangerous!

24. Comments are dangerous!