OOP – Object Oriented Programming

OOP – Object Oriented Programming

• Object-oriented Programming, or OOP for short, is a programming paradigm which provides a means of structuring programs so that properties and behaviors are bundled into individual objects.
• Object-oriented programming is an approach for modeling concrete, real-world things like cars as well as relations between things like companies and employees, students and teachers, etc.
• OOP models real-world entities as software objects, which have some data associated with them and can perform certain functions.
• Python is an object oriented language.
• It provides us a programming environment where we can create objects and can perform operations on them.
• The main features of object oriented language are
  • Data Abstraction and Encapsulation
  • Inheritance
  • Polymorphism

Class

• A class is a blue print of an object.
• We can say it is generic description of an Object.

class classname:
  Data Members
  ------------
  Member Functions
  ------------

Data members

• It indicates information about the object or current state of Object.
• Data members must be created in setter methods or constructors.
• Data members are automatically created when value is assigned to them in member functions.

Member functions:

• It indicates the operations that we perform on the object.
• The self-parameter is a reference to the object itself, and is used to accessmembers that belongs to the object.
• It does not have to be named self, you can call it whatever you like, but it has to be the first parameter of any function in the class.

def function-Name(self,argument1,argument2,...):
  Statements
  ----------
  return value

Setter methods

• Generally setter methods are used to initialize objects.
• In python they are also used to create data members.
• Generally their name starts with word set.

def setPropertyName(self,argument1,argument2,...):
  self.datamember = argument1
  self.datamember = argument2

• Data members
• Length
• Breadth
• Member Functions
• setDimension(x,y)
• Area()
• Perimeter()

class Rectangle:
  def setDimension(self,x,y):
    self.length = x
    self.breadth = y
  def area(self):
    a = self.length*self.breadth
    print("Area is",a)
  def perimeter(self):
    p=2*(self.length+self.breadth)
    print("Perimeter is ",p)

• Data members
• Length
• Breadth
• Height
• Member Functions
• setDimension(x,y,z)
• volume()

class box:
  def setDimension(self,x,y,z):
    self.L = x
    self.B = y
    self.H = z
  def volume(self):
    v = self.L*self.B*self.H
    print("Volume is ",v)

• Data members
• radius
• Member Functions
• setRadius(n)
• Area()
• circumference()

class circle:
  def setradius(this,n):
    this.R = n
  def area(this) :
    a =3.14*this.R**2
    print("Area is ",a)
  def circumference(this):
    c =2*3.14*this.R
    print("Circumference is",c)