the best way to store my statistics (ruby)

Question

I want to display some statistics of data stored in array of arrays. I have three categories (video,article,webinar) but it could expand later on. The structure of statistics per category will be almost the same. Like: total number of videos, last date when added new record in category, etc.

So far I can think of a hash of an array to store the stats. Where the array would hold the structure of stats per category and would be the (almost) same for all categories. Could anybody think of any better solution in terms of

• being easy to include new category
• easy to manipulate/assign/calculate all the statistical data
• easy to display

my idea looks like

stats = { 'video' = [], 'article' = [], 'webinar' = [] } 
stats_array = ['Total number','Last date added','etc']

and then I would do something like

stats['video'][stats_array.index('Total number')] +=1

Answer 1

Use an object oriented solution! It has little coding overhead, but allows for easy expansion etc. Perhaps create a Statistics class, then a class ArticleStatistic < Statistics class etc. You might not need all that power early, but it's cleaner and more expandable.

Answer 2

I voted for Peter's answer :-)

Here is an example ... (updated to have a to_s rather than a print helper, which didn't get pasted in anyway) ... (updated again for sorting/array question) ...

class Stats
  attr_accessor :type, :count, :last_date;
  def initialize t
    @type = t
  end
  def to_s
    "%-9s %4d %s" % [@type, @count, @last_date]
  end
  def <=> other
    [@type, @last_date, @count] <=> [other.type, other.count, other.last_date]
  end
end

all = []
v = Stats.new 'video'
v.count = 12
v.last_date = 'Tuesday'
all << v
a = Stats.new 'article'
a.count = 5
a.last_date = 'Monday'
all << a

puts v
puts a
puts "Ask, and ye shall be sorted..."
puts all.sort
$ ruby r5.rb
video       12 Tuesday
article      5 Monday
Ask, and ye shall be sorted...
article      5 Monday
video       12 Tuesday
$