From: x1 <caldridge@...>
Date: 2006-10-12T12:44:20+09:00
Subject: Re: Counting Frequency of Values in an Array (And Sorting by Frequency?)

and.. so you're aware.. my hacky code was something like this:

items = {}
["a", "a", "a", "b", "c", "c"].each do |i|
   if items.include? i
     items[i] += 1
   else
     items[i] = 1
   end
end

items.sort {|a,b| a[1]<=>b[1]}.reverse.each do |a, b|
	puts a + ":" + b.to_s
end


horrific eh?





On 10/11/06, x1 <caldridge@gmail.com> wrote:
> Wow Capaldo, that worked! I fear for the next java programmer who has
> to make sense of my code when I leave ;-)
>
> To reverse sort, I added .reverse..  Here's the final product:
> puts ["a", "a", "a", "b", "c", "c"].inject(Hash.new(0)) { |hash, item|
> hash[item] += 1
>  hash }.sort_by { |k, v| v }.reverse.map { |k, v| "#{k}:#{v}" }
>
> Thanks so much.
>
> Nakada, I look forward to using it in 1.9 :-)
>
> On 10/11/06, Nobuyoshi Nakada <nobu@ruby-lang.org> wrote:
> > Hi,
> >
> > At Thu, 12 Oct 2006 11:52:19 +0900,
> > x1 wrote in [ruby-talk:219218]:
> > > Is there no method for an array that will tell me the # of occurrences
> > > for an item?
> > >
> > > IE:  ["a", "a", "a", "b", "c", "c"].count("a") #producing 3 ?
> >
> > FYI, Enumerable in 1.9 has that method.
> >
> > --
> > Nobu Nakada
> >
> >
>