> For the complete documentation index, see [llms.txt](https://harshityadav95.gitbook.io/system-design/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://harshityadav95.gitbook.io/system-design/s.o.l.i.d-principles.md).

# S.O.L.I.D Principles

Violating DRY in code  ??

![](/files/q3jDIXi3VKdyRAEYvHow)

**S.O.L.I.D** is an acronym for the **first five object-oriented design(OOD) principles** .These principles, when combined together, make it easy for a programmer to develop software that are easy to maintain and extend. They also make it easy for developers to avoid code smells, easily refactor code, and are also a part of the agile or adaptive software development.

1. ***S***RP The Single Responsibility Principle: — a class should have one, and only one, reason to change, meaning that a class should have only one job.
2. ***O***CP The Open Closed Principle: — you should be able to extend a class’s behavior, without modifying it.
3. ***L***SP The Liskov Substitution Principle: — If any module is using a Base class then the reference to that Base class can be replaced with a Derived class without affecting the functionality of the module.
4. ***I***SP The Interface Segregation Principle: — make fine grained interfaces that are client specific.
5. ***D***IP The Dependency Inversion Principle — depend on abstractions not on concrete implementations.

Video Playlist  : <https://youtube.com/playlist?list=PL9sRG84iY01HXb8BiMghlGG0VH_tENssx>

Reference  : &#x20;

* Github repo <https://github.com/wtvamp/ThemeParkSOLIDApp>
* Each Branch of the repository is a Implementation