The SOLID principles are a set of best practices for object-oriented design that focus on creating software with high maintainability and reusability through managing dependencies and responsibilities, including the single responsibility, open-closed, Liskov substitution, interface segregation, and dependency inversion principles. Following these principles helps create flexible, robust software by reducing coupling between modules and increasing cohesion within modules. Adhering to SOLID makes code more readable, maintainable, and predictable when changes need to be made.

1. The SOLID PrinciplesReading Geek Night

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3. What the?An acronym of acronymsCollection of best-practicesloose-couplingMaintainabilityPrinciples – not RulesFocus on dependency management

4. Dependency managementPoor dependency managementHard to changeFragileNon-reusableGood dependency managementFlexibleRobustReusable

5. Single Responsibility PrincipleA class should have one, and only one, reason to change

6. Single Responsibility PrincipleBenefitsMore readable codeMore robustMore maintainableSmaller functions

7. Open Closed PrincipleSoftware entities should be open for extension, but closed for modification

8. Open Closed PrincipleChange to an entity cascades changes to dependent modules

9. Fragile

10. Unpredictable

11. Modules should never change

12. Extend behaviour – add new code

13. Don’t change existing working codeLiskov Substitution PrincipleDerived classes must be substitutable for their base classes

14. Liskov Substitution PrincipleImportant for any program conforming to OCP

15. Caller should not be surprised by substituting base type for subtype

16. Virtual members must exist in derived classes

17. Must do useful + expected workLiskov Substitution PrincipleUseful work