Welcome to this unit! Let's dive into the SOLID principles in software design, which are critical for creating maintainable, scalable, and robust software systems.

Here are some example questions you might encounter during an interview:

• Can you explain the SOLID principles in software design?
• Why are these principles important, and how do they enhance software design?
• Can you provide examples of each SOLID principle?

By mastering these questions, you'll be well-equipped to showcase your understanding of SOLID principles and their practical applications in software development.

The SOLID principles are a set of five design principles aimed at improving software design's modularity, flexibility, and scalability. Here's an overview of each principle, along with why they are essential:

1. Single Responsibility Principle (SRP):

   • What it is: A class should have only one reason to change, meaning it should only have one responsibility or job.
   • Why it matters: SRP makes your classes more manageable and easier to understand, which simplifies maintenance and reduces the risk of bugs.
   • Example: Consider a User class responsible for user data. Handling email notifications for the user should be in a separate Notification class.

2. Open/Closed Principle (OCP):

   • What it is: Software entities should be open for extension but closed for modification.
   • Why it matters: OCP allows you to add new functionality without changing existing code, reducing the risk of introducing bugs.
   • Example: Use interfaces or abstract classes to allow new implementations without altering existing ones.