Code reading workshop JUG Switzerland - March 14th, 2023 https://maritvandijk.com/ 

Welcome! https://maritvandijk.com/presentations/code-reading/jug-ch-2023-03-14/ 1. Join the Miro Board 2. Select annotation method: * On paper * Annotation tool * Download file Try to refrain from reading the code for now! 

Code reading workshop Agenda • Welcome! • Setting the scene 

Code reading workshop Setting the scene (1) (2 mins) Independently - Note down one thing about today's code reading club session in a sticky note... ... that you are looking forward to or excited about ... that you are worried or confused about 

Code reading workshop Setting the scene (2) (5 mins) Together - Discuss Give everyone a chance to read out their hopes and fears Use the remaining time to discuss collectively what you want to get out of the session 

Code reading workshop Agenda • Welcome! • Setting the scene • First glance • Code structure • BREAK • Content • Summary • Re fl ect 

Code reading workshop First glance (1) The goal of this exercise is to practice to get a fi rst impression of code and to act upon that. We all have di ff erent instincts and strategies for where to start when faced with a new piece of code. It doesn't matter how trivial you think the fi rst and second things you noticed are. (1 min) Independently - Glance at the code It's important that this is an immediate reaction. Right away, note down the fi rst thing that catches your eye. Then note down the second thing that catches your eye. Take the remainder of the minute to think about why you noticed those things fi rst. 

Code reading workshop First glance (2) (5 mins) Together - Discuss the results Talk about why things might have jumped out for di ff erent people. • How do those initial observations help with deciding what to look at next? • What lines or facts or concepts were chosen by everyone versus by only a few people? Re fl ect also on what kind of knowledge you used in this exercise: • Knowledge of the domain, of the programming language? Of a framework? • What knowledge do you think might be needed to better understand this code? 

Code reading workshop Code Structure (1) The goal of this exercise is to be a concrete thing to do when looking at new code for the fi rst time. New code can be scary, doing something will help! (12 mins) Independently - Examine structure Variables Go through the code and circle all variables in red Then draw a link between variables and their uses Function / method calls Go through the code and circle all methods in blue Then draw a link between methods and their invocations Instantiation Go through the code and circle all instances of classes in green Then draw a link between classes and their instances 

Code reading workshop Code Structure (2) (10 mins) Together - Discuss the results • Did anyone have trouble deciding what constituted a variable, function or class? • What patterns are visible from the colors and links only? • How does the data fl ow through the code? • What parts of the code seem to warrant more attention? 

Code reading workshop Content (1) The goal of this exercise is to start to think about which lines in the code de fi ne its essence, have the biggest impact or need to be paid close attention to. (8 mins) Independently - Identify most important lines Brie fl y discuss what it means to be important as a group (if you want to) Then, identify the 5 lines you consider most important 

Code reading workshop Content (2) (10 mins) Together - Discuss Discuss in the group: • Lines covered by many people? • Lines named but not by a lot of people • Agree on less than 8 of the most important lines • Take turns in the group, and let every member talk about the code for 30 seconds (or less/more, could also be one sentence each). Try to add new information and not repeat things that have been said, and repeat until people do not know new things anymore. 

Code reading workshop Summary (1) The goal of this exercise is to think about the core purpose or function of this code. (5 mins) Independently - Summarize Try to write down the essence of the code in a few sentences 

Code reading workshop Summary (2) (10 mins) Together - Discuss • Topics covered by many vs few • Strategies used to create the summary (e.g. method names, documentation, variable names, prior knowledge of system) 

Code reading workshop Re fl ect on the session Let's wrap up the session with a little re fl ection (5 mins) Together - note down things about the session • What went well or felt good? • What would you to try to do di ff erently next time because they didn't work or felt bad? 

Code reading workshop Next steps (1) If we have time, we can optionally discuss the following (5 mins) Together - Discuss Now that you have attended this workshop, would you consider doing this more often? Why / why not? What would you get out of doing code reading sessions? 

Code reading workshop Links https://maritvandijk.com/presentations/code-reading/