patterns to avoid code duplication
Aaron Wang
Rule of the thumb: Don't Repeat!
- Hard to read, all seem similar, are there any differences or not?
- Too much details are spread everywhere, can not find the key point, headaches!
- Hard to change, you might change some of them, forget the others, cause inconsistency, therefore bugs
- No one dare to change, so more duplication, everyone tends to write new code instead of reuse, it will get worse and worse
- It's literally the biggest enemy to code maintainability
Extract small functions
- Clean functions
- Utility functions & classes
class inheritance
- Put common things in base class, while children can override if needed
- Template method pattern
- Use polymorphism to avoid if/else
- Don't go for it just for code reuse, only when it's appropriate
class composition
- When inheritance is not right
ASpect oriented programming
- Programming is about data process, imagine a pipe of data you can filter, intercept
- Common cases:
- Authentication check
- Error handling
- Logging
- i18n
patterns to avoid code duplication Aaron Wang
