Could you demonstrate an example for each of the main paradigms of object-oriented programming?

The main paradigms of object-oriented programming (OOP) are encapsulation, inheritance, and polymorphism. Here is an example in C# for each:

Encapsulation — hiding internal implementation and providing access through methods:

class BankAccount
{
    private decimal balance;

    public void Deposit(decimal amount)
    {
        if (amount > 0)
            balance += amount;
    }

    public decimal GetBalance()
    {
        return balance;
    }
}

Inheritance — creating a new class based on an existing one:

class Animal
{
    public virtual void Speak() => Console.WriteLine("Some sound");
}

class Dog : Animal
{
    public override void Speak() => Console.WriteLine("Bark");
}

Polymorphism — the ability to use objects of different classes through a common interface:

void MakeAnimalSpeak(Animal animal)
{
    animal.Speak();
}

MakeAnimalSpeak(new Dog()); // Outputs "Bark"

These examples demonstrate the key concepts of OOP in C#.