OOP Advanced

1. Inheritance

Inheritance me ek class (Child) dusri class (Parent) ke attributes aur methods inherit karti hai. Ye reusability ke liye use hota hai.

class Animal:
    def __init__(self, name):
        self.name = name

    def speak(self):
        print(self.name, "makes a sound")

class Dog(Animal):
    def speak(self):
        print(self.name, "barks")

dog = Dog("Tommy")
dog.speak()

Output:

Tommy barks

2. super() Keyword

super() ka use parent class ke constructor/method call karne ke liye hota hai.

class Vehicle:
    def __init__(self, brand):
        self.brand = brand

class Car(Vehicle):
    def __init__(self, brand, model):
        super().__init__(brand)
        self.model = model

c = Car("Toyota", "Corolla")
print(c.brand, c.model)

Output:

Toyota Corolla

3. Polymorphism

Polymorphism ka matlab hai alag-alag classes me same method ka different behavior.

class Cat(Animal):
    def speak(self):
        print(self.name, "meows")

animals = [Dog("Tommy"), Cat("Kitty")]

for a in animals:
    a.speak()

Output:

Tommy barks
Kitty meows

4. Encapsulation

Encapsulation ka matlab hai internal details ko hide karna aur sirf methods ke through access dena.

class BankAccount:
    def __init__(self, balance):
        self.__balance = balance   # private variable

    def deposit(self, amount):
        self.__balance += amount

    def get_balance(self):
        return self.__balance

account = BankAccount(1000)
account.deposit(500)
print(account.get_balance())

Output:

1500

Summary

• Inheritance: code reuse
• super(): parent access
• Polymorphism: same method, different behavior
• Encapsulation: data hiding