This document discusses concepts of clean code adapted for JavaScript. It defines clean code as code that is elegant, efficient, simple, direct, and can be understood and enhanced by developers other than the original author. It provides guidelines for writing clean code, including: using intention-revealing, explanatory, pronounceable, searchable and consistent naming; keeping functions small and focused on a single task; limiting function arguments; avoiding side effects; following the DRY principle; and using functional programming over imperative programming. Classes should also be small and follow the single responsibility principle. Method chaining is also recommended. Resources and code samples are provided from books and repositories on clean code.

1. CONCEPTS OF CLEAN CODE ADAPTED
FOR JAVASCRIPT
by
Jennifer Zeiser

2. [1]

3. What is Clean Code?
“I like my code to be
elegant and efficient. […]
Clean Code does one
thing well.”
Bjarne Stroustrup
(inventor of C++) [2]
“Clean code is simple
and direct. Clean code reads
like well-written prose.” Grady Booch
(inventor of UML) [3]

4. What is Clean Code?
Dave Thomas
(founder of OTI) [4]
Dave Thomas
(author of
“The Pragmatic
Programmer”) [5]
“Clean code can be
read, and enhanced by a
developer other than its
original author.”

5. [6]

6. “There are only two hard things in
Computer Science: cache
invalidation and naming things.”
Phil Karlton [7]

7. Intention-revealing names

8. Intention-revealing names

9. Explanatory names

10. Pronounceable names

11. Searchable names

12. Searchable names

13. Avoid mental mapping

14. Avoid mental mapping

15. Consistent names

16. Don’t add unnecessary
context

17. Don’t add unnecessary
context

18. Meaningful names
•Intention-revealing
•Explanatory
•Pronounceable
•Searchable (no magic numbers, strings, …)
•Explicit (avoids mental mapping)
•Consistent (one word per concept)
•Without unnecessary context

19. “The first rule of functions is that they
should be small.
The second rule of functions is that
they should be even smaller than that.”
Robert C. Martin [8]

20. Functions should do one thing

21. Functions should do one thing

22. Function arguments
“The ideal number of arguments for
a function is zero (niladic). Next
comes one (monadic), followed
closely by two (dyadic).
Three arguments (triadic) should be
avoided where possible. More than
three (polyadic) requires very
special justification […]”Robert C. Martin [8]

23. Function arguments: polyadic

24. Function arguments: flags

25. Function arguments: flags

26. Avoid Side Effects I

27. Avoid Side Effects I

28. Avoid Side Effects II

29. Don’t repeat yourself

30. Don’t repeat yourself

31. No monkey patching

32. Functional over imperative
programming

33. Functional over imperative
programming

34. “The first rule of classes is that they
should be small.
The second rule of classes is that they
should be even smaller than that.”
Robert C. Martin [8]

35. Prefer ES2015 (ES6) classes

36. Single Responsibility Principle

37. Single Responsibility Principle

38. Use method chaining

39. Use method chaining

40. Resources
• Clean Code - A Handbook of Agile Software
Craftsmanship by Robert C. Martin
• Clean Code Javascript by Ryan McDermot

41. Code samples
• Code samples were partially adapted from the book
“Clean Code: A Handbook of Agile Software
Craftsmanship” by Robert C. Martin, as well as from the
Github repository “clean-code-javascript” by Ryan
McDermott
• Remaining code samples were created by the author or
taken from the “real-world” with permission of the
respective creators

42. Images
• [1] https://www.thenile.com.au/books/robert-c-martin/clean-code-a-handbook-of-
agile-software-craftsmanship/9780132350884
• [2] https://www.technologyreview.com/s/407076/bjarne-stroustrup/
• [3] https://en.wikipedia.org/wiki/Grady_Booch
• [4] https://confengine.com/user/dave-thomas-2
• [5] https://en.wikipedia.org/wiki/Dave_Thomas_(programmer)
• [6] https://www.reddit.com/r/ProgrammerHumor/comments/7ym547/
the_only_valid_measurement_of_code_quality_is/
• [7] https://www.nndb.com/people/400/000031307/
• [8] https://en.wikipedia.org/wiki/Robert_C._Martin

43. Thank you
for your attention!
Any questions?