SOLID design principles

This brings us to another interesting concept in OOP called SOLID design principles. These design principles apply to any OOP design and are intended to make software easier to understand, more flexible, and easily maintainable.

The term SOLID is a mnemonic for:

• Single responsibility principle
• Open/closed principle
• Liskov substitution principle
• Interface segregation principle
• Dependency inversion principle

In this chapter, we will only take a look at the first two principles—the single responsibility principle and the open/closed principle. Let's look at the single responsibility principle next.