Python – Class & Objects

🔷 Python – Class & Objects (Easy Hinglish Notes)

🔸 Class kya hoti hai?

Class ek design hoti hai — blueprint jiske base par hum objects banate hain.

Example: Car ek class hai — lekin actual car (Maruti, Honda) object hai.

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🔸 Object kya hota hai?

Object class ka real example hota hai — jiske paas properties (data) aur functions (methods) hote hain.

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🔸 Syntax of Class and Object:

class ClassName:
    def __init__(self):
        # constructor
        print("Object bana")

# object create karna
obj = ClassName()

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🔸 Example 1 – Simple Class:

class Student:
    def __init__(self):
        print("Student object created")

s1 = Student()

🟢 Output:

Student object created

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🔸 Example 2 – Class with Attributes:

class Student:
    def __init__(self, name, marks):
        self.name = name
        self.marks = marks

    def show(self):
        print("Name:", self.name)
        print("Marks:", self.marks)

s1 = Student("Navghan", 90)
s1.show()

🟢 Output:

Name: Navghan
Marks: 90

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🔸 __init__() kya hota hai?

• Ye ek special function (constructor) hai jo object banate hi automatic call hota hai.

• self ka matlab hota hai — current object.

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🟨 Practice Exercises with Solutions

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✅ Exercise 1:

Ek class Car banao jisme brand aur price ho, aur ek method ho show() details print karne ke लिए।

class Car:
    def __init__(self, brand, price):
        self.brand = brand
        self.price = price

    def show(self):
        print("Brand:", self.brand)
        print("Price:", self.price)

c1 = Car("Honda", 800000)
c1.show()

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✅ Exercise 2:

Ek class Circle banao jo radius le aur area return kare.

class Circle:
    def __init__(self, radius):
        self.radius = radius

    def area(self):
        return 3.14 * self.radius * self.radius

c = Circle(5)
print("Area of circle:", c.area())

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✅ Exercise 3:

Ek class Person banao jo naam aur umar rakhe aur ek method greet() ho jo Hello Navghan, your age is 21 jaise print kare.

class Person:
    def __init__(self, name, age):
        self.name = name
        self.age = age

    def greet(self):
        print(f"Hello {self.name}, your age is {self.age}")

p = Person("Navghan", 21)
p.greet()

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अगर तुम चाहो तो मैं aur bhi practice exercises, MCQs, ya ek mini project (like Student Management System) bhi bana सकता हूँ। बताओ कैसे आगे बढ़ना है?