SOLID principles Explained - Easy to Understand

The SOLID principles are a set of five principles of object-oriented programming that were first introduced by Robert C. Martin in his 2000 paper "Design Principles and Design Patterns." The SOLID principles are intended to help developers create maintainable, scalable, and extensible software. The acronym SOLID stands for:

1. Single Responsibility Principle (SRP): This principle states that a class should have only one reason to change, meaning that it should have only one responsibility. This helps to keep the class simple and focused, making it easier to understand, test, and maintain.

2. Open-Closed Principle (OCP): This principle states that a class should be open for extension but closed for modification, meaning that new functionality should be added by creating new classes rather than modifying existing ones. This helps to ensure that existing functionality is not affected when new functionality is added.

3. Liskov Substitution Principle (LSP): This principle states that objects of a superclass should be able to be replaced with objects of a subclass without affecting the correctness of the program. This helps to ensure that subclasses are interchangeable with their superclasses and that the program can be easily extended.

4. Interface Segregation Principle (ISP): This principle states that a class should not be forced to implement interfaces it does not use. It means creating smaller interfaces that are more specific to the class that is implementing them. This helps to keep the interface simple and focused, making it easier to understand and use.

5. Dependency Inversion Principle (DIP): This principle states that high-level modules should not depend on low-level modules, but rather both should depend on abstractions. This helps to decouple the modules, making the program more flexible and easier to maintain.

These principles are all interrelated and they should be followed together to achieve best results. They provide a guideline for designing software systems that are easy to understand, maintain, and extend. Following SOLID principles leads to software that is less prone to bugs, more scalable, and easier to test.