SOLID: Design principles of Object-Oriented Design

Software engineers often find it very hard to refactor or change a piece of code, even if they understand the codebase thoroughly. The change could be as simple as fixing a bug, or as complex as switching to a completely new architecture.

Changes in software projects are inevitable. It is expected from us engineers to not only learn how to code but also learn how to organize, structure and design the codebase. This would help in creating and maintaining a solid but flexible codebase, which is easy to change quickly and reliably.

However, it’s easier said than done.

SOLID principles are a set of well-known design principles that can make software understandable, flexible and maintainable.

These principles are only a subset of principles promoted by Robert C. Martin (Uncle Bob). The SOLID principles have become the core philosophy for methodologies like agile development. When applied properly, these principles can make your code readable, extendable and maintainable.

Developers tend to ignore the importance of SOLID. Many developers might not even be aware of these 5 design principles which are extremely important. As a developer, you should not only be aware of these principles but also possess a good understanding of them and know when and how to apply them.

Understanding and applying all the SOLID principles every day is hard. You will need a lot of reading and practice to be a master of this very important aspect of software programming and design.

The 5 SOLID principles

  • S: Single Responsibility Principle
  • O: Open-Closed Principle
  • L: Liskov Substitution Principle
  • I: Interface Segregation Principle
  • D: Dependency Inversion Principle

We will cover these principles in detail with lots of examples. Stay tuned.