Ruby is a pure object oriented language and everything in ruby is an object of some class. In ruby we can create classes and create objects of the classes. In the below example we will create 3 classes Person, Address and Company. An object of a class can be created with public method new. Internally this public method(new) calls private method initialize. Initialize works as a constructor of the class.

Setter method: The setter method sets the value of instance variable for the object. Getter method: The getter method get the value of instance variable of the object

class Person
  def initialize(name, age, email, gender)
    @name = name
    @age = age
    @email = email
    @gender = gender
    @addresses = []
  end

  def add_new_address(address)
    addresses << address
  end

  def name
    @name
  end

  def age
    @age
  end

  def email
    @email
  end

  def gender
    @gender
  end

def addresses
    @addresses
  end
end

class Address
  def initialize(city, zip, country)
    @city = city 
    @zip = zip 
    @country = country
  end
  def city
    @city
  end

  def zip
    @zip
  end

def country
    @country
  end
end

class Company
  def initialize(name, address)
    @name = name
    @address = address
    @employees = []
  end

  def employees
    @employees
  end

def add_employee person
    employees << person
  end
end

Using classes to create objects:

creating objects of address class

address1 = Address.new("Delhi", 110018, "India")
address2 = Address.new("Dehradun", 248001, "India")
address2 = Address.new("Punjab", 258008, "India")

creating objects of person class

person1 = Person.new('Martin', 22, "martin@yahoo.com", "Male")
person2 = Person.new('Virat', 22, "virat@yahoo.com", "Male")
person3 = Person.new('Priya', 22, "priya@yahoo.com", "Female")

adding address to person

person1.add_new_address(address1)
person1.add_new_address(address2)

person2.add_new_address(address3)
person2.add_new_address(address2)

person3.add_new_address(address3)
person3.add_new_address(address1)

creating objects of company class and add employees

company = Company.new("Evontech", address2)
company.add_employee(person1)
company.add_employee(person2)
company.add_employee(person3)

showing all employees of company

company.employees

first employee

company.employees[0]

name of first employee

company.employees[0].name

addresses of first employee

company.employees[0].addresses

last address of first employee

company.employees[0].addresses[-1]