solid
SOLID Principles
Five core principles of object-oriented design that lead to systems which are simpler to maintain, test, and extend. Robert C. Martin (Uncle Bob) formalized these ideas, and Michael Feathers coined the SOLID acronym.
Principle Index
| Principle | Summary | Reference |
|---|---|---|
| S — Single Responsibility | A class should have only one reason to change | reference |
| O — Open/Closed | Open for extension, closed for modification | reference |
| L — Liskov Substitution | Subtypes must be substitutable for their base types | reference |
| I — Interface Segregation | Prefer many specific interfaces over one general-purpose interface | reference |
| D — Dependency Inversion | Depend on abstractions, not concretions | reference |
Why SOLID Matters
Without SOLID, codebases gradually develop these problems:
- Rigidity — one change ripples through many unrelated modules
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