In object-oriented development, there is an important set of principles called SOLID. While it is possible to develop without adhering to them, following these principles leads to more efficient development and easier maintenance.
In fact, calling them “extremely” important is not an exaggeration. Therefore, it is recommended to study and understand these principles, always keeping them in mind when creating and modifying new features. By the time you fully grasp these principles, you will likely have become a “software programmer” rather than just a “coder - feature implementer.”
SOLID is not literally meant to mean “solid” or “hard” but is an acronym formed by the first letters of five important principles. The meaning of each letter is as follows. If you don’t understand what this means just by looking at this part, that’s normal.
- S: Single Responsibility Principle
- A class should have only one reason to change.
- O: Open-Closed Principle
- Classes should be open for extension but closed for modification.
- L: Liskov Substitution Principle
- Subtypes must be substitutable for their base types without altering the correctness of the program.
- I: Interface Segregation Principle
- Interfaces should be separated by role.
- D: Dependency Inversion Principle
- The dependency between the implementation and usage of a class should be inverted by abstraction.