Creating Multiple Objects in Ruby and then Comparing Them - ruby

My goal is to be able to assign each tea their own ID, compare prices and weights between teas, and do it all within the command line. What's a smart way to do this? Here is my code so far:
class Tea
def initialize(name, price, shipping, weight)
#name = name
#price = price
#shipping = shipping
#weight = weight
get_tea_details
#total_price = total_price
end
def get_tea_details
puts "Enter name: "
#name = gets.chomp
puts "Enter price: "
#price = gets.chomp.to_f
puts "Enter shipping cost: "
#shipping = gets.chomp.to_f
puts "Enter weight: "
#weight = gets.chomp.to_i
end
def total_price
#total_price = #price + #shipping
end
def price_difference
price_difference = t1.total_price - t2.total_price
print "#{price_difference}"
end
end
puts "Do you want to compare teas?: "
answer = gets.chomp
if answer == "yes"
t1 = Tea.new(#name, #price, #shipping, #weight)
t1 = Tea.new(#name, #price, #shipping, #weight)
end
price_difference

I'm not exactly sure what you're asking, but my guess is you want to know how to write a function to compare your Tea objects. You can do something like this:
class Tea
attr_accessor :name, :price
def price_difference(other)
print (#price - other.price).abs
end
def compare(other)
same = true
if(#name != other.name)
puts "They have different names."
same = false
end
if(#price != other.price)
puts "They have different prices."
same = false
end
if same
puts "They are exactly the same!"
end
end
end
t1 = Tea.new
t2 = Tea.new
t1.compare t2
"They are exactly the same!"
I'd also recommend dropping the "tea_" prefix from your variables. It's unnecessary and adds a little readability.

Related

Ruby labeling printed outputs

I'm writing a short program that asks a user to enter a car model, maker, and year input and it passes that input through an algorithm. My question is, is there a way to label multiple printed outputs after it has been put through the formula to where it will number each output? Would I have to use a for each loop? I'm just trying to get a general idea of how I would accomplish this.
say for example the printed output would look like this.
class Car
attr_reader :make, :model, :year
def initialize
end
def set_make(make)
#make = make
end
def set_model(model)
#model = model
end
def set_year(year)
#year = year
end
def get_make
#make
end
def get_year
#year
end
def get_model
#model
end
end
array_of_cars = Array.new
print "How many cars do you want to create? "
num_cars = gets.to_i
for i in 1..num_cars
puts
print "Enter make for car #{i}: "
make = gets.chomp
print "Enter model for car #{i}: "
model = gets.chomp
print "Enter year of car #{i}: "
year = gets.to_i
c = Car.new
c.set_make(make)
c.set_model(model)
c.set_year(year)
array_of_cars << c
end
puts
puts "You have the following cars: "
puts
for car in array_of_cars
puts "#{car.get_year} #{car.get_make} #{car.get_model}"
end
puts
2014 Ford Expedition
2017 Toyota 86
2017 Aston Martin DB11
is there a way to add those numbers to the output?
Instead using a for loop you could try using each_with_index, which will allow you to get each element inside the array_of_cars and also the index for each element, in this case adding 1 to the current index will give you the value starting from 1:
array_of_cars.each_with_index do |car, index|
puts "#{index + 1}. #{car.get_year} #{car.get_make} #{car.get_model}"
end
Or you can use each and with_index passing the first element, in this case 1 as argument:
array_of_cars.each.with_index(1) do |car, index|
puts "#{index}. #{car.get_year} #{car.get_make} #{car.get_model}"
end
You don't need so many methods. Use attr_accessor to set getters and setters and utilize initialize better. Then using the basic idea from this answer by tadman, we can collect newly made objects into an array within the class itself. All together we can compress your class to:
class Car
attr_accessor :make, :model, :year
def self.all
#all ||= []
end
def initialize(make, model, year)
#make = make
#model = model
#year = year
Car.all << self
end
end
We can use times to run a piece of code n times.
puts "How many cars do you want to create? "
n = gets.to_i
n.times.with_index(1) { |_,i|
puts "Enter make for car #{i}"
make = gets.chomp
puts "Enter model for car #{i}: "
model = gets.chomp
puts "Enter year of car #{i}: "
year = gets.to_i
puts
Car.new(make, model, year)
}
Then as Sebastián Palma has already suggested, use each.with_index(1) to print your cars. The argument offsets the index by 1.
Car.all.each.with_index(1) { |c, i| puts "#{i}. #{c.year} #{c.make} #{c.make}" }
Sidenotes: 1. Avoid using for loops in Ruby 2. Use puts not print.

Using a variable across classes in Ruby

I have this class:
class Player
attr_accessor :card_pile, :name
def initialize
#name = name
#bust = false
#card_pile = []
end
def bust?
return #cards.inject(:+) > 21
end
end
I also have this as the beginning of another class
def playing_game
puts "How many players are playing? "
players_amount = gets.chomp.to_i
(0...players_amount).each do
puts ("What is the players name? ")
#name = gets.chomp
#players.push(#name)
end
#players.each do |each_player|
#name = Player.new
while true
while #name.card_pile.length < 2 do
new_card = Card.new
#name.card_pile.push(new_card.value)
end
puts(#name.card_pile)
print #name, "'s turn" "\n"
At the moment this will print out #<Player:0x007fc14984a4b0>'s turn instead of Rich's turn
Why is this happening? I thought I had made an instance variable in the Player class and then instantiated this class #name = Player.new and then could reference it from here on out??
This will help
def playing_game
puts 'How many players are playing?'
players_amount = gets.chomp.to_i
players_names = (0...players_amount).map do
puts ("What is the players name? ")
gets.chomp
end
players_names.each do |player_name|
player = Player.new(player_name)
while player.card_pile.length < 2 do
new_card = Card.new
player.card_pile.push(new_card.value)
end
puts player.card_pile
puts "#{player.name}'s turn"
end
end
UPD:
You don't need instance variables (like #name and #players inside single method).
In this code you iterate over players names
#players.each do |each_player|
=>
players_names.each do |player_name|
In context of
#name = Player.new
name is a Player instance
to create player with given name pass it to initializer:
player = Player.new(player_name)
then call name on Player instance, that you create earlier
puts "#{player.name}'s turn"

Ruby - Making my code object orientated

I'm just starting out with OOP and am struggling to work out how to implement it. I can't work out how to create an instance of the class using the hash.new method. It's a basic program that takes input from a user and stores it in a hash. I was then planning on pushing the hash into an array to take advantage of the index. Below is the code
class Customer
def initialize(id, name, address, phone, email, bank_balance)
#id = id
#name = name
#address = address
#phone = phone
#email = email
#bank_balance = bank_balance
end
end
puts "Would you like to create an account?"
answer = gets.chomp
loop do
new_hash = {}
if answer.downcase.start_with?('y')
puts "Enter your name"
name = gets.chomp.downcase
new_hash['name'] = name
puts "Enter your address"
address = gets.chomp.downcase
new_hash['address'] = address
puts "Enter your ph number"
number = gets.chomp
number = number.split.join
new_hash['number'] = number
puts "Enter your email"
email = gets.chomp.downcase
new_hash['email'] = email
puts "Enter your bank balance"
bank_balance = gets.chomp
bank_balance = "$" + '%.2f' % bank_balance
new_hash['bank_balance'] = bank_balance
customer << new_hash
binding.pry
puts "Thankyou, details successfully Added"
break
else
break
end
end
you should remove everything inside initialize(...) and instead use
attr_accessor :name, :address, :phone, :email, :bank_balance) write it above your initialize statement
for more information on attr_accessor see this post What is attr_accessor in Ruby?
also follow it up by reading up on attr_reader and attr_writer
you can then assign values to those initialized variables in the rest of your code.
you will call your class by running Customer.new
you can get a little more snap out of your code by assigning your gets.chomp values to additional methods, then you can do something like
class Customer
attr_accessor :name, :address, :phone
def initialize
#name = ''
#address = ''
#phone = ''
end
def name
puts "Enter your name"
name = gets.chomp.downcase
end
def address
puts "Enter your address"
address = gets.chomp.downcase
end
def phone
puts 'enter your phone'
phone = gets.chomp
phone = phone.split.join
end
def all
name
address
phone
end
end
customer = Customer.new
customer.all

How can I combine two blocks to simplify my code?

Hi I am a student learning Ruby. I am using the quick start guide at ruby-lang.org, which has some examples of Ruby basics.
I studied the MegaGreeter class, and I am trying to figure out how to puts two arguments (name and age) in the same each block in order to simplify my code.
I think there would be another way. (Using regular loops instead of each.)
Calculate the array's size.
Use a loop like in C.
But I want to use the each loop. Below is my code:
class MegaGreeter
attr_accessor :name
attr_accessor :age
#Creat the object
def initialize(name=nil, age=0)
#name = name
#age = age
#tmp = Array.new()
#i = 0
end
#Say hi to everybody
def say_hi
if #name.nil?
puts "please give me the input !!"
elsif #name.respond_to?("each")
#list responding
#name.each do |name|
#tmp[#i] = "hi ~! #{name}"
#i += 1
end
#i=0
#age.each do |age|
#tmp[#i] += " and you are #{age} years old"
puts #tmp[#i]
#i += 1
end
else
puts "give me array ~"
end
end
end
a = MegaGreeter.new()
a.name = ["juno","yoonhe"]
a.age = [1,2]
a.say_hi
You can use the Array method zip to first combine your two arrays. It groups the elements by their position in the array, so the first element of the #name array will be grouped with the first element of the #age array and so on.
#name = ['Foo', 'Bar']
#age = [23, 41]
name_and_age = #name.zip(#age)
# [['Foo', 23], ['Bar' 41]]
Now the names and ages are grouped together, and you can iterate over them using each.
name_and_age.each do |name, age|
puts name, age
end
# Foo 23
# Bar 41
Putting it back into your original code:
class MegaGreeter
attr_accessor :name, :age
#Creat the object
def initialize(name = nil, age = 0)
#name = name
#age = age
end
#Say hi to everybody
def say_hi
if #name.nil?
puts "please give me the input !!"
elsif #name.respond_to?("each")
#list responding
#name.zip(#age).each do |name, age|
puts "hi ~! #{name} and you are #{age} years old"
end
else
puts "give me array ~"
end
end
end

How can user input dynamically create objects?

I would like users to be able to dynamically create objects of the Incomes class below. That is, I would like to fire my program and let users enter as many incomes as they like, all stored as instances of the Incomes class.
def prompt
puts "> "
end
class Incomes
def initialize(aName, aAmount, aCOLA)
#name = aName
#amount = aAmount
#COLA = aCOLA
end
end
def addIncome
puts "What is the company name?"
prompt
aName = gets.chomp
puts "What is the monthly amount?"
aAmount = gets.chomp
puts "What is the cost of living adjustment?"
aCOLA = gets.chomp
end
#Now I want to be able to loop back through addIncome and create as many objects as the
#user wants. Perhaps there's a better way to store this type of data?
def prompt question
print "#{question} > "
gets
end
class Incomes
attr_reader :name, :amount, :COLA
##instances_of_Incomes = Array.new
def initialize(aName, aAmount, aCOLA)
#name = aName
#amount = aAmount
#COLA = aCOLA
#instances_of_Incomes = Array.new
end
def self.addIncome
name = prompt "What is the company name?"
amount = prompt "What is the monthly amount?"
_COLA = prompt "What is the cost of living adjustment?"
##instances_of_Incomes << Incomes.new(name, amount, _COLA)
end
def self.instances
##instances_of_Incomes
end
end
5.times do
Incomes.addIncome
end
puts Incomes.instances
Incomes.instances.each do |company|
puts company.name
end
I have refactored the code to show that you can use inputs to create the instances. They are unnamed classes, but stored in a class variable.
I also show that you can extract the name of each Incomes instance.
I have also edited your SE Code Review question, with the same code, so hopefully you can get some good reviews.

Resources