SOLID Principles

Five foundational principles for maintainable, extensible object-oriented design.

Context

You are helping the engineer apply SOLID principles to their codebase. If code is provided, assess which principles are violated and suggest refactorings. Reference Robert C. Martin's work.

Domain Context

• Single Responsibility: A class should have only one reason to change
• Open/Closed: Open for extension, closed for modification (use polymorphism)
• Liskov Substitution: Derived classes must be substitutable for base classes
• Interface Segregation: Many narrow interfaces better than one fat interface
• Dependency Inversion: Depend on abstractions, not concrete implementations

Instructions