Ruby: Array of Objects/Classes

Question

I am not a ruby expert and this is giving me trouble. But how Would I go about creating an array of objects/classes in ruby? How would initialize it/declare it? Thanks in advance for the help.

This is my class, and I want to create an array of it:

class DVD
  attr_accessor :title, :category, :runTime, :year, :price

  def initialize()
    @title = title
    @category = category
    @runTime = runTime
    @year = year
    @price = price
  end
end

Answer 1

Ruby is duck typed (dynamic typing) And almost everything is an object, so you can just add any object to an array. For example:

[DVD.new, DVD.new]

will create an array with 2 DVDs in it.

a = []
a << DVD.new

will add the DVD to the array. Check the Ruby API for the full list of array functions.

Btw, if you want to keep a list of all the DVD instances in the DVD class you can do this with a class variable, and add it to that array when you create a new DVD object.

class DVD
  @@array = Array.new
  attr_accessor :title, :category, :runTime, :year, :price 

  def self.all_instances
    @@array
  end

  def initialize()
    @title = title
    @category = category
    @runTime = runTime
    @year = year
    @price = price
    @@array << self
  end
end

now if you do

DVD.new

you can get the list of all the DVDs you have created so far:

DVD.all_instances