Hi all, welcome to another coding blog!
Today we are going to talk about things you can define, like a car, a dog, a person,.. All these “things” can be called objects. Object-oriented programming(OOP) is a very important programming model and one of the harder parts to get your head around.
Object-oriented programming (OOP) is a programming language model organized around objects rather than “actions” and data rather than logic.
I won’t explain everything into to much detail as I am very tired from coding 8hours+ the last four days. But here are the basics of today.
Want more information about classes and objects? Click here
Example of a Class, and the creation of an object of that class. And a more complex Class that uses the initialize method. Including the creation of an object with passing the required parameters.
### Create a class Car###
class Car
end
### Create an object of the Car class ###
car = Car.new
---------------------------------
### Create a class Car which needs two parameters, defined in the initialize method. ###
### The initialize method gets called whenever an object is created. ###
class Car
def initialize(make, wheels)
@make= make
@no_of_wheels= wheels
end
end
### Create an object of the Car class with two parameters. ###
car = Car.new("Porsche",4)
For the most part of the day we had one big exercise, namely creating a program for a pizzeria. Every step of the exercise we got less and less explanation in order to challenge us to use everything we learned. And I can tell you the steps got harder and harder to complete. There were quite a few moments I really didn’t see a solution and had to redo parts and reread chapters of the reader. Below you can see my final version of the pizzeria and all the different files needed to make the program.
Click on the different tabs to see to different files:
require "./waiter"
require "./menu"
require "./kitchen"
menu = Menu.new
kitchen = Kitchen.new
waiter = Waiter.new(menu, kitchen)
waiter.greet_guest
while(waiter.still_serving) do
waiter.serve_guest
waiter.order_food(gets.chomp.to_i)
end
require "./check"
class Waiter
def initialize(menu, kitchen)
@menu = menu
@kitchen = kitchen
@check = Check.new
@serving = true
end
def greet_guest
puts "Good day. Welcome to our lovely restaurant."
end
# run method take_order and pass user input as the order_number argument
def serve_guest
puts "How can I be of service?"
puts "1. Would you like to order a pizza?"
puts "2. Would you like to leave?"
take_order(gets.chomp.to_i)
end
def take_order(order_number)
case order_number
when 1
puts "Let me get the menu"
list_menu
when 2
@check.calculate_check
puts "Thank you for you visit"
@serving = false
else
puts "I really don't understand"
end
end
def list_menu
@menu.contents.each_with_index do |dish, index|
puts "#{index}. #{dish.name} \t € #{dish.price}"
end
end
def order_food(choice)
dish = @menu.contents[choice]
if @kitchen.order(dish)
@check.add(dish)
puts "Dish is on its way"
else
puts "Sorry this dish is not available"
end
end
def still_serving
@serving
end
end
class Menu
require "./dish"
require "./ingredient"
def initialize
@menu = []
@menu << Dish.new("Margherita", [
Ingredient.new(Ingredient::TOMATO, 3),
Ingredient.new(Ingredient::DOUGH, 0.25),
Ingredient.new(Ingredient::MOZZARELLA, 0.2)
], 9)
@menu << Dish.new("Napoletana", [
Ingredient.new(Ingredient::TOMATO, 3),
Ingredient.new(Ingredient::DOUGH, 0.25),
Ingredient.new(Ingredient::MOZZARELLA, 0.2),
Ingredient.new(Ingredient::ANCHOVIES, 0.05)
], 11)
@menu << Dish.new("Peperoni",[
Ingredient.new(Ingredient::TOMATO, 3),
Ingredient.new(Ingredient::DOUGH, 0.25),
Ingredient.new(Ingredient::MOZZARELLA, 0.2),
Ingredient.new(Ingredient::PEPERONI, 0.1)
], 12)
end
def contents
@menu
end
end
class Dish
def initialize(dish_name, ingredients, price)
@name = dish_name
@ingredients = ingredients
@price = price
end
def name
@name
end
def ingredients
@ingredients
end
def price
@price
end
end
require './storage'
class Kitchen
def initialize
@storage = Storage.new
end
def order(dish)
puts "KITCHEN: Order received for #{dish.name}"
puts "I'm gonna need some:"
dish.ingredients.each do |ingredient|
puts "#{ingredient.amount} _ #{ingredient.name}"
end
@storage.fetch(dish.ingredients)
end
end
class Ingredient
TOMATO = "Tomato"
DOUGH = "Dough"
MOZZARELLA = "Mozzarella"
ANCHOVIES = "Anchovies"
PEPERONI = "Peperoni"
def initialize(name,amount)
@name = name
@amount = amount
end
def name
@name
end
def amount
@amount
end
def use(amount)
@amount -= amount
end
end
class Storage
def initialize
@items = [
Ingredient.new(Ingredient::TOMATO, 8),
Ingredient.new(Ingredient::DOUGH, 2),
Ingredient.new(Ingredient::MOZZARELLA, 1),
Ingredient.new(Ingredient::PEPERONI, 0.3)
]
end
def fetch(ingredients)
ingredients.each do |ingredient|
item = @items.detect{|item| item.name == ingredient.name}
if item
item.use ingredient.amount
else
return false
end
end
end
end
class Check
def initialize
@items = []
end
def add(item)
@items << item
end
def calculate_check
puts "Your check"
puts "-" * 20
sum = 0
@items.each do |item|
p "#{item.name} € #{item.price}"
sum += item.price
end
puts "-" * 20
puts "Total price: € #{sum}"
puts "-" * 20
end
end
