OOP Basics Lecture

car.rb

# car.rb

# filename - lower_snake_case
# class name - UpperCamelCase

# sports_car.rb => SportsCar

class Car
  attr_reader :brand
  # attr_writer :color
  attr_accessor :color # attr_reader + attr_writer

  # contructor — method that will be called on Car.new
  def initialize(color, brand)
    # instance variables - DATA
    @engine_started = false
    @color = color
    @brand = brand
  end

  # Instance methods - BEHAVIOUR
  def engine_started?
    @engine_started
  end

  def start_engine
    start_spark_plugs
    turn_on_battery
    check_fuel

    @engine_started = true
  end

  # attr_reader :brand

  # explicit getters / readers

  # def color
  #   @color
  # end

  # def brand
  #   @brand
  # end

  # def paint_car(new_color)
  #   @color = new_color
  # end

  # explicit setters / writers

  # def color=(new_color)
  #   @color = new_color
  # end

  def car_info
    "This car is a #{@color} #{@brand}"
  end

  private

  def start_spark_plugs
    puts "1. STARTING SPARK PLUGS"
  end

  def turn_on_battery
    puts "2. TURNING ON BATTERY"
  end

  def check_fuel
    puts "3. CHECKING FUEL"
  end
end

car_test.rb

# car_test.rb

require_relative 'car'

# creating a new Car instance
car = Car.new('red', 'Ferrari')

puts "Engine started: #{car.engine_started?}"

car.start_engine
# car.start_spark_plugs
# car.check_fuel

puts "Engine started: #{car.engine_started?}"

puts "My car is a #{car.color} #{car.brand}"

# paint my car green

# car.paint_car('green')

car.color = 'green' # is just a car.color=('green') call

puts "My car is a #{car.color} #{car.brand}"

debugging.rb

# debugging.rb

require 'pry-byebug'

# gem install pry-byebug
# require 'pry-byebug'
# insert binding.pry calls

# commands:
#   * next - execute the next line
#   * continue - continue till the end or to the next
#                binding.pry call
#   * !!! - exit

def full_name(first, last)
  # binding.pry
  first_name = first.capitalize

  last_name = last.capitalize

  [first_name, last_name].join(' ')
end

puts full_name('paul', 'buzzfeed')