BLOC Intro to Classes

Intro to Classes

#CP1

class Book
  def title_and_author(title, author)
    # set title to instance variable
    # set author to instance variable
    @title = title
    @author = author
  end
  
  def description    
    # return a string with both instance variables
    # "Title was written by author
    "#{@title} was written by #{@author}"
  end
end

#instance methods && instance variables are the same thing?

#RSpec

describe "Book" do
  describe "description" do
    it "should return title and author in description" do
      book = Book.new
      book.title_and_author("Ender's Game","Orson Scott Card")
      book.description.should eq("Ender's Game was written by Orson Scott Card")
    end
  end
end

#CP2

class Book
  #settable
  def title=(t)
    @title = t
  end
  
  def pages=(p)
    @pages = p
  end
  
  def author=(a)
    @author = a
  end
  
  #gettable
  def title
    @title
  end
  
  def pages
    @pages
  end
  
  def author
    @author
  end
end

#RSPEC

describe "Book" do
  describe "instance variables" do
    it "should be able get and set the title to 'LOTR'" do
      b = Book.new
      # Ability to get/set title
      b.title = "LOTR"
      b.title.should eq("LOTR")
      # Ability to get/set pages
      b.pages = 1000
      b.pages.should eq(1000)
      # Ability to get/set author
      b.author = "J. R. R. Tolkien"
      b.author.should eq("J. R. R. Tolkien")
    end
    it "should be able to set the title to 'Hitchhiker's Guide'" do
      b = Book.new
      # Ability to get/set title
      b.title = "Hitchhiker's Guide"
      b.title.should eq("Hitchhiker's Guide")
      # Ability to get/set pages
      b.pages = 700
      b.pages.should eq(700)
      # Ability to get/set author
      b.author = "Douglas Adams"
      b.author.should eq("Douglas Adams")
    end
  end
end

#CP2

class Playlist
  attr_accessor :name
  attr_accessor :author
  attr_accessor :song_list
end

#RSpec

describe "Playlist" do
  describe "instance variables" do
    it "should be able to create a country playlist" do
      p = Playlist.new
      
      # Setters
      p.name = "Country"
      p.author = "Blake Shelton"
      p.song_list = ["Sure Be Cool If You Did", "God Gave Me You"]

      # Getters
      p.name.should eq("Country")
      p.author.should eq("Blake Shelton")
      p.song_list.should eq(["Sure Be Cool If You Did", "God Gave Me You"])
    end
    it "should be able to create a Rock playlist" do
      p = Playlist.new
      
      # Setters
      p.name = "Rock"
      p.author = "R&R"
      p.song_list = ["Radioactive", "Clouds"]

      # Getters
      p.name.should eq("Rock")
      p.author.should eq("R&R")
      p.song_list.should eq(["Radioactive", "Clouds"])
    end
  end
end

instance methods && instance variables are the same thing?

class Foo
def bar(a,b,c)
@A= a
@b=b
@c=c
end
end