Classes and Objects

Classes and objects are the foundation of Object-Oriented Programming (OOP).

They help you structure your code in a clean, reusable, and organized way.

WHAT IS A CLASS?

A class is a blueprint or template used to create objects.

It defines:

• Attributes (variables)
• Methods (functions)

Example of a Class

class Car:
    pass

This is a simple class named Car.

WHAT IS AN OBJECT?

An object is an instance of a class.

It represents a real-world entity created from a class.

class Car:
    passcar1 = Car()
print(type(car1))

Here, car1 is an object of the Car class.

CLASS WITH ATTRIBUTES (USING CONSTRUCTOR)

The constructor method __init__() initializes object data.

class Car:
    def __init__(self, brand, color):
        self.brand = brand
        self.color = colorcar1 = Car("Toyota", "White")
print(car1.brand)
print(car1.color)

Explanation:

• __init__ runs automatically when object is created
• self refers to the current object
• brand and color are attributes

CLASS WITH METHODS

Methods are functions defined inside a class.

class Car:
    def __init__(self, brand):
        self.brand = brand    def start(self):
        print(self.brand, "car is starting.")car1 = Car("Honda")
car1.start()

Here:

• start() is a method
• It uses object data

MULTIPLE OBJECTS

You can create many objects from one class.

car1 = Car("Toyota")
car2 = Car("BMW")car1.start()
car2.start()

Each object has its own data.

REAL-WORLD ANALOGY

Class = Blueprint of a house
Object = Actual house built from that blueprint

Class = Student
Objects = Hira, Ali, Ahmed

KEY DIFFERENCE

Class	Object
Blueprint	Instance
Defined once	Created multiple times

WHY USE CLASSES AND OBJECTS?

• Organize large programs
• Make reusable code
• Model real-world systems
• Improve maintainability

KEY TAKEAWAY

A class defines structure and behavior.
An object is a real instance created from that class.

Understanding classes and objects is the first major step in mastering OOP in Python.