Example.rb

require "pry"

class Appointment
  attr_accessor :date, :patient, :doctor
  @@all = []

  def initialize(date, patient, doctor)
    @date = date
    @patient = patient
    @doctor = doctor
    @@all << self
  end

  def self.all
    @@all
  end
end

class Doctor
  attr_accessor :name

  def initialize(name)
    @name = name
    @@all << self
  end

  def new_appointment(patient, date)
    # given a date and a patient, creates a new appointment
    Appointment.new(date, patient, self)
  end
end

class Patient
  attr_accessor :name
  @@all = []

  def initialize(name)
    @name = name
    @@all << self
  end

  def new_appointment(doctor, date)
    Appointment.new(date, self, doctor)
  end
end

# Use the appointment class to make a new appointment.
johnson = Doctor.new("Dr. James Johnson")
kody = Patient.new("Kody Clemens")
first_appointment = Appointment.new(Time.now.strftime("%Y-%m-%d"), kody, johnson)
binding.pry

# Use the doctor new_appointment instance method to create an appointment, given a patient and a date.
carl = Patient.new("Carl Nicholson")
johnson.new_appointment(carl, Time.now.strftime("%Y-%m-%d"))
binding.pry

# Use the patient new_appointment instance method to create an appointment, given a doctor and a date.
weaver = Doctor.new("Dr. Alex Weaver")
kody.new_appointment(Time.now.strftime("%Y-%m-%d"), weaver)
binding.pry

# The last line in the ruby file cannot be binding.pry. You can ignore the puts "foo".
puts "foo"