C# is built on object-oriented programming (OOP), which is powered by three main ideas.
🔒 Encapsulation
Keep data safe inside a class.
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class BankAccount
{
private decimal balance; // Only accessible inside BankAccount
public void Deposit(decimal amount)
{
balance += amount;
}
public decimal GetBalance()
{
return balance;
}
}
🧬 Inheritance
Let one class build on another.
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class Animal
{
public void Eat() => Console.WriteLine("Eating...");
}
class Dog : Animal
{
public void Bark() => Console.WriteLine("Woof!");
}
Dog d = new Dog();
d.Eat(); // From Animal
d.Bark(); // From Dog
🔁 Polymorphism
One interface, many forms.
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class Animal
{
public virtual void Speak() => Console.WriteLine("Animal sound");
}
class Cat : Animal
{
public override void Speak() => Console.WriteLine("Meow");
}
Animal a = new Cat();
a.Speak(); // Meow
📝 Why it matters
- Encapsulation: Protects data.
- Inheritance: Reuses code.
- Polymorphism: Makes code flexible.
Next: Access modifiers in C#!
