The SOLID principles are a set of software design guidelines that help developers write maintainable, scalable, and robust code. These principles were introduced by Robert C. Martin (Uncle Bob) and form the foundation of many modern programming best practices.
This article will cover each of the SOLID principles in C# with examples.
1. Single Responsibility Principle (SRP)
Each class should have only one reason to change, meaning it should focus on a single responsibility. This keeps the code modular and easier to understand, test, and maintain.
2. Open/Closed Principle (OCP)
A class should be open for extension but closed for modification. This means you can add new functionality to a class without altering its existing code, often achieved through abstraction or inheritance.
3. Liskov Substitution Principle (LSP)
Subtypes must be substitutable for their base types. This ensures that a derived class can be used wherever the base class is expected, without changing the behavior of the program.
4. Interface Segregation Principle (ISP)
A class should not be forced to implement interfaces it doesn't use. Instead of creating one large interface, break it into smaller, more specific interfaces to avoid unnecessary dependencies.
5. Dependency Inversion Principle (DIP)
High-level modules should not depend on low-level modules; both should depend on abstractions. This promotes loose coupling in the system by relying on interfaces or abstract classes rather than concrete implementations.
