DRY, KISS, YAGNI — and their limits
On This Lesson 4 topics
The content for this lesson is written and waiting for review. The outline below shows what it covers. It will be published once it is approved.
In this lesson
apply three rules and know when they clash.
Planned topics
- DRY: do not repeat the same knowledge in many places.
- KISS: keep it simple; the simplest design that works.
- YAGNI: do not build things you do not need yet.
- Conflict: removing small duplication can make code more complex (DRY against KISS).
- Rule of thumb: wait for the third repeat before you abstract; similar code is not always the same knowledge.
Draft outline details
Demonstration
two similar methods; one merge that needs a flag parameter and gets harder to read.
Check your understanding
When do you abstract repeated code?
Show answer
When the same idea appears about three times and is really the same.
Practice
Apply this lesson with the module's lab, exercises and quiz.
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