It was a bright morning at the University of Computer Sciences. Students were filling the lecture hall, chatting excitedly about the topic of the day - Object-Oriented Programming (OOP). The lecturer, a seasoned software developer and an enthusiastic educator named Professor Richard, walked in, his face beaming with a smile.

“Good morning, everyone,” Professor Richard greeted, and the room quieted down. “Today we’ll journey through two of the most important concepts in OOP - Composition and Inheritance.”

The class settled, eagerly awaiting the insightful session. Richard asked, “Who can tell me how to create a new console project in Visual Studio?”

Sophia, a bright student, promptly raised her hand and narrated the steps flawlessly. Richard nodded approvingly.

“Excellent, Sophia. We’ll need that for our hands-on examples. But first, let’s discuss reusability in OOP.”

Reusability in OOP

“In OOP,” he began, “we have two primary methods for achieving code reusability - Inheritance and Composition. They are fundamentally different in their approach and implications. Let’s unravel them one by one.”

Inheritance in OOP

“Inheritance, class,” Richard started, “is when a class, say ‘Mammal’, inherits properties and behaviors from another class, say ‘Animal’. This relationship is defined as an ‘is-a’ relationship. A Dog, for instance, is a Mammal and is thus an Animal.”

He continued, “Inheritance brings several advantages, such as extensibility, code redundancy minimization, and ensuring a standard interface. But it also carries disadvantages, including increased coupling and potential encapsulation violation.”

“Let’s see an example,” Richard said as he began typing on his laptop connected to the projector.

public class Animal
{
    public string Name { get; set; }
    public string Habitat { get; set; }
    public string Diet { get; set; }
}

public class Mammal : Animal
{
    // Additional mammal-specific properties and methods
}

public class Dog : Mammal
{
    // Additional dog-specific properties and methods
}

He explained, “Here, ‘Mammal’ is a subclass of ‘Animal’, and ‘Dog’ is a subclass of ‘Mammal’. This is a typical example of Inheritance.”

Composition in OOP

“Next, we have Composition,” Richard continued. “Composition is a ‘has-a’ relationship. For instance, a Library has Books.”

He typed another example on his laptop.

public class Book
{
    public string Title { get; set; }
    public string Author { get; set; }
}

public class Library
{
    private List<Book> books = new List<Book>();
    // Other properties and methods
}

He turned to the class, “Here, ‘Library’ is a class that contains a list of ‘Book’ objects. This is a typical example of Composition.”

Why Prefer Composition Over Inheritance?

“Now, the million-dollar question,” Richard paused, “When should we use Composition, and when should we use Inheritance?”

He continued, “When you design base classes for inheritance, you’re providing a common interface. But this brings certain challenges such as subclass adherence to base class implementations, difficulty in changing the base class over time, and increased coupling.”

“In most cases, Composition is favored due to its loose coupling. But remember, it’s not a hard-and-fast rule. Sometimes Inheritance can be a better choice. The key is understanding the specific requirements of your application and designing your classes