Short viva

Alright Maham, here's a full easy-breezy OOP viva prep — everything important in bullet points 👇
Keep this flow in your mind for viva — sounds confident, humble, and to the point.

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🔹 Definition

• OOP stands for Object-Oriented Programming

• It's a method of writing code using objects (like real-world things)

• It makes code modular, reusable, secure, and easy to manage

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🔹 Core Concepts (4 Pillars)

1. Class

   • Blueprint or design of an object

   • Eg: Car class has color, speed, engine type

2. Object

   • Real thing created from a class

   • Eg: myCar = Car() → This is an object

3. Encapsulation

   • Wrapping data + functions inside one unit

   • Hides internal details (like a capsule)

   • Uses private/public access

4. Inheritance

   • Child class gets features of parent class

   • Reduces code repetition

   • Eg: Dog inherits from Animal

5. Polymorphism

   • One function behaves in different ways

   • Eg: draw() can draw circle or square

   • Types: Compile-time (overloading), Run-time (overriding)

6. Abstraction

   • Hides complex logic, shows only necessary part

   • Eg: You drive a car without knowing engine code

   • Uses abstract classes/interfaces

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🔹 Other Important Concepts

• Constructor

  • Special function that runs when object is created

  • Eg: __init__() in Python, same name as class in Java/C++

• Destructor

  • Cleans up memory when object is destroyed

• Method Overloading (Same name, different parameters - compile time)

• Method Overriding (Same name, same parameters - runtime)

• Access Modifiers

  • Control who can access what

  • public, private, protected

• Interface

  • Just like a contract: tells what must be done

  • No body, only function names — class must implement it

• Abstract Class

  • Has some code + some functions without code

  • Cannot make object of abstract class

• Static

  • Belongs to class, not object

  • Eg: static int count = 0;

• This / Self

  • Refers to current object

  • this in Java/C++, self in Python

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🔹 Benefits of OOP

• Real-world modelling

• Reusability

• Easy maintenance

• Secure coding

• Less redundancy

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Want viva-ready one-liners or examples also?