SOLID Principles 🗿

The SOLID principles are design principles that help create maintainable object-oriented software. SOLID stands for:

Principle	Description	Example
Single Responsibility	A class/module should have only one reason to change. It should have a single responsibility.	A class that parses and validates input. Split into two classes.
Open Closed	Software entities should be open for extension but closed for modification.	A payment processor that supports new payment methods via new classes rather than change.
Liskov Substitution	Objects should be replaceable by their subtypes without affecting program behavior.	A rectangle class that can be substituted for a square class without issue.
Interface Segregation	Client specific interfaces are better than one general purpose interface.	Separate mouse/keyboard interfaces instead of one input device interface.
Dependency Inversion	Depend on abstractions rather than concretions.	Depend on a persistence interface rather than a MySQL class.

Benefits

Improved maintainability
Change accommodation
Testability
Loose coupling

SOLID guides developers to create software with components that are cohesive, reusable and maintainable. Applying SOLID can take practice but pays off in long term code quality.