Reading code (Dev2Next)

As developers, we spend a lot of time learning to write code, while spending little to no time learning to read code. Meanwhile, we often spend more time reading code than actually writing it. Shouldn’t we be spending at least the same amount of time and effort improving this skill? Deliberate practice can help us get better at reading code. Learning how to better read and understand code, can in turn teach us what makes code readable. This might even help us to write code that is easier to read.

In this talk we will discuss the benefits of deliberately practicing reading code in a code reading club or session without an IDE, as well as common strategies to navigate a new codebase and familiarise ourselves with the code using the IDE.

Transcript

1. Reading Code Dev2Next, Oct 3rd 2024 https://maritvandijk.com/
2. Reading Code • We spend more time reading code than writing code
3. Reading Code We read code when: • adding features • fi xing bugs • understanding a new system • doing code reviews • learning new technologies • etc.
4. Reading Code "developers on average spend as much as 58% of their time comprehending existing source code" - Felienne Hermans, The Programmer's Brain
5. Reading Code • We spend more time reading code than writing code • But we don't practice reading code explicitly (much)
6. Readability When we do talk about readability, it's often about writing readable code.
7. Reading Code "How to teach programming (and other things)?" by Felienne Hermans https://www.youtube.com/watch?v=g1ib43q3uXQ
8. Reading Code • What if we practice reading code explicitly?
9. Code Reading Club • Code Reading Club https://codereading.club/
10. The stars aligned Do you want to join our code reading club?
11. Code Reading Club • Printed code sample • Structured exercises
12. Examples of exercises • First glance (1 min.)
13. Code reading exercise First glance The goal of this exercise is to practice getting a fi rst impression of code. (1 min) Independently - Glance at the code Note down the fi rst thing that catches your eye. Then note the second thing that catches your eye. Think about why you noticed those things fi rst.
14. 1 min.
16. Examples of exercises • First glance • Identify components & relationships
17. Examples of exercises • First glance • Identify components & relationships • Most important lines
18. Examples of exercises • First glance • Identify components & relationships • Most important lines • Identify concepts
19. Examples of exercises • First glance • Identify components & relationships • Most important lines • Identify concepts • Summary
20. Code Reading Club Learned about ... • reading code
21. Code Reading Club Learned about ... • reading code • other peoples' perspectives
22. Code Reading Club Learned about ... • reading code • other peoples' perspectives • making my own assumptions explicit https://maritvandijk.com/code-reading-club/
23. Reading Code
24. Reasons why code is confusing 1. Lack of knowledge 2. Lack of information 3. Lack of processing power in the brain
25. Cognitive processes • Long term memory • Short term memory • Working memory
26. Lack of knowledge • Programming domain • Language / syntax • Programming constructs / algorithms • Business domain • Domain concepts • Business logic
27. Dealing with a lack of knowledge • Create a list • Research • Memorise (if relevant)
28. Lack of information • Unknown details • Unfamiliar names • Code connected in unknown ways • Too many things at once
29. Dealing with lack of information • Chunking
30. Dealing with lack of information • Chunking • Concepts & patterns
31. Lack of processing power in the brain • Too many processing steps • Too many variables
32. Dealing with lack of processing power in the brain • Memory aids • Dependency graph • State table
33. Dependency graph
34. State table public class NestedLoop { public static void main(String[] args) { for (int i = 0; i < 2; i++) { System.out.println("i is: " + i); for (int j = 0; j < 2; j++) { System.out.println("j is: " + j); } } } }
35. Dimensions of code reading • Structure • Domain • Concepts • Context 💔
36. Structure Code is not read linearly
37. Domain • Behavior • Data
38. Concepts
39. Context
40. Reading Code The bigger picture
41. Understanding a new code base • Joining a new team / organisation • Using a new code base
42. Reading Code • What does the code do?
43. Context
44. Reading Code A good place to start: • Check out the code
45. Help in the IDE
46. Help in the IDE • Project structure • Build & run • README • Dependencies • Diagrams
47. Strategies • Identify components • Identify relationships / dependencies • Identify concepts • Gain context
48. A slice of the application
49. Find a starting point
50. Find a starting point • Generic • Main method • Endpoint • Speci fi c • Error message / Exception • Logic / Functionality
51. Help in the IDE
52. Help in the IDE • Search • Navigate
53. Strategies • A particular use case • Draw your own diagrams
54. Reading Code Understanding a piece of code
55. Reading Code • Structured exercises
56. Help in the IDE
57. Help in the IDE • Structure • Hints from your IDE • Tests • Debugging • Refactor for understanding • Context
58. Strategies • Structured exercises • Memory aids • Dependency graph • State table • Gain context
59. Reading Code What's next?
60. Structured exercises • Code Reading Club: https://codereading.club/ • Code Reading Club Resources: https://github.com/CodeReadingClubs/Resources • The Programmer's Brain - Felienne Hermans
61. Let your tools help you
62. ... and your brain
63. Reading code Slides & More https://maritvandijk.com/presentations/reading-code/