Intro
Imagine inheriting a massive, poorly designed codebase. Every change you make breaks something else. For software developers, such nightmares can be avoided by adhering to the SOLID principles, a foundational guideline for creating maintainable, scalable systems. These principles are a must-know for any software developer seeking to improve the quality of their work. They provide a roadmap for developers to create cleaner, more maintainable codebases, which is why I was drawn to this resource
Blog Summary
The blog goes through each of the five principles, explaining what they are, why they are important, and giving a code examples utilizing each one.
1. Single Responsibility Principle (SRP): A class should have only one reason to change, ensuring focused and cohesive functionality. The blog illustrates SRP with an example of separating user management from content creation, showing how this approach simplifies debugging and enhances code clarity.
2. Open-Closed Principle (OCP): Software entities should be open for extension but closed for modification, promoting adaptability without risking existing functionality. For OCP, the blog demonstrates how using inheritance and interfaces allows developers to add new functionality, using Square and Rectangle classes inheriting from the Shape base class.
3. Liskov Substitution Principle (LSP): Subtypes must be substitutable for their base types without altering the correctness of the program. The example provided for LSP highlights how properly designed subclasses, such as an Eagle and a Penguin inheriting from a Bird class, ensure seamless substitution without breaking the program.
4. Interface Segregation Principle (ISP): Clients should not be forced to depend on interfaces they do not use, encouraging lean and specific interfaces. In discussing ISP, the blog uses an example of splitting a large interface into smaller, more specific ones, ensuring that classes only implement what they actually need.
5. Dependency Inversion Principle (DIP): High-level modules should not depend on low-level modules but instead rely on abstractions. For DIP, the blog explains how decoupling high-level modules from low-level details using abstraction layers, like interfaces, makes the codebase more flexible and easier to maintain.
Why I chose this resource
I selected this blog to write about because it breaks down each principle in a concise way, clearly explaining each one in a way that is easy to understand at all levels. It’s a great resource to quickly go back to when you need a refresher on any of the principles.
Reflection on SOLID
After learning about SOLID, I see that it might take an extra step of thinking to adhere to the principles at first, but I think it’s well worth it for the resulting code structure. The easy way to code is messily throwing together code that works without a second thought, but doing that is very dangerous for the longevity of a program. I believe that after following SOLID for a while it will become second nature and will become the natural way of coding, which is why I think it’s important to learn about SOLID early and consciously until it does become a subconscious practice. In one of my past projects, I struggled with messy code that implemented multiple responsibilities in one class. Debugging it was a nightmare, but had I known about the SRP principle it could have been avoided entirely. Reflecting on these principles has already influenced how I plan on approaching my code, and I’m eager to incorporate them into my future work.
Future Application
Given the importance of SOLID principles for large-scale software, I believe it’s essential to internalize and apply them in future projects to thrive in the software development space. By crafting modular classes and reducing dependency, I aim to create services and systems that are easy to maintain and adapt as requirements expand and evolve.
Citation
“Essential Software Design Principles You Should Know Before the Interview” By Arslan Ahmad
From the blog CS@Worcester – The Science of Computation by Adam Jacher and used with permission of the author. All other rights reserved by the author.