What is OOPs ?

OOP stands for Object-Oriented Programming.

It organizes code using objects, bundling data and methods together. Encapsulation protects data, inheritance promotes code reuse, and polymorphism allows the use of a common interface for different object types. It enhances code structure and flexibility in software development.

Advantage of OOPs ?

  • OOPs programming paradigm is considered as a better style of programming.
  • OOP is faster and easier to execute.
  • It allows us the reusability of code.
  • OOP helps to keep the C++ code DRY "Don't Repeat Yourself", and makes the code easier to maintain, modify and debug.
  • Reduce the complexity. 

What are Classes and Objects?

Class : A class is a blue print that define the variable and the methods common to all entities of a certain kind , collection of objects is called class , it's a logical entity. 

Objects : Objects is a real world entity that has state and behaviour , state - data store in variable , behaviour -  functionality define in method . for example - a chair , pen , table , it can be physical or logical.




So, a class is a template for objects, and an object is an instance of a class.
When the individual objects are created, they inherit all the variables and functions from the class.

Different between class and object ? 

  1. Class is used as a template for declaring and creating the object. an object is a variable of a class . 
  2. A class is a logical entity , an object is a physical or logical entity . 
  3. When class is created no memory is allocated . object are allocated memory space whenever they are created . 
  4. A class can not be manipulated as they are not available in the memory . object can be manipulate.
  5.  The class has to be declared only once , an object is created many times as per requirement . 
CONSTRUCTOR : A constructor is a special method of a class which is automatically executed when an object of a class is created ,its name is same as class name ,it's has no return type . it is used to initialized the object . 

Even if we don't define any constructor ,then the compiler will automatically provide a default constructor, constructor should be define in a public section .

Parameterized Constructors : The constructor having a specific number of parameter to be passed . 
Default Constructor : When it does not have any parameter .
Overloading Constructors : multiple constructors have the same name as long as the number or type of parameter are different .

A class can have multiple constructors but the number and type of parameter must be different .
 
DESTRUCTOR : is a special method of a class which deletes an object and free up memory , the destructor neither takes any parameters not returns any value . 

Access Specifiers : 

Private access specifiers : Member can not be accessible outside the class .
Public access specifiers : Member are accessible outside the class . 
Protected access specifiers : Member are only accessible in the inherited class . 

ENCAPSULATION : 
Refers to wrapping up of similar data and functionalities into a single unit .

The meaning of Encapsulation, is to make sure that "sensitive" data is hidden from users. To achieve this, you must declare class variables/attributes as private (cannot be accessed from outside the class). If you want others to read or modify the value of a private member, you can provide public get and set methods.


INHERITANCE : 
The capability of class to inherit attributes and methods from one class to another is called inheritance . inheritance to reduce code redundancy by creating a superclass person . 

We group the "inheritance concept" into two categories -
  • The class that inherits properties from another class is called child class or derived class or sub class .
  • The class whose properties are inherited by a child class is called parent class or base class or super class . 
Advantages of Inheritance :
  1. Reduce code redundancy. 
  2. increases code reusability. 
  3. Save time and effort as the main code present in the super class, not need to written again. 
Type of Inheritance :
Single : One super class one sub class
Multilevel : A class can also be derived from one class which is already derived from Another class.
Multiple : Multiple super class and single sub class.
Hierarchical : Single super class and multiple sub class
Hybrid : Combining various type of inheritance like multiple , simple and hierarchical inheritance is known as hybrid inheritance.

POLYMORPHISM : 
Polymorphism means "many forms", is a feature of oops that allows the object to behave differently in different conditions . a women is a responsible mother , employee , and customer .

Type of Polymorphism : 
  1. Compile time ( function overloading ) .
  2.  Runtime ( function overriding ,virtual function ) .
In compile time polymorphism the call is resolved by compiler , in runtime polymorphism the call is not resolved by the compiler . 

function overloading : multiple function can have the same name as long as the number and type of parameter are different . 
function overriding is a feature of oops that allow us to override a function of parent class in child class , its a example of runtime polymorphism . 


ABSTRACTION : 
refers to hiding the implementation details of a particular functionalities .