From: "Brian Schröder" <ruby@...>
Date: 2004-11-10T01:21:53+09:00
Subject: Re: Iterating trough hash

Hello Kevin,

as the hash key is unique it should suffice to do it like this. 

h = {"john" => 41, "mary" => 31, "fred" => 10}
h.each do | person1, age1 |
  h.each do | person2, age2 |
    next if person1 <= person2
    puts "#{person1} shakes hands with #{person2}. Together they are #{age1 + age2} years old"
  end
end

Note that you made an error with the string interpolation. I assume you are coming from php where you only need the $, here in ruby we need the braces.

Regards,

Brian


On Wed, 10 Nov 2004 01:08:38 +0900
Kevin B�rgens <kevin@boergens.de> wrote:

> Hi!
> 
> This is my first ruby day. I started reading the ruby book two hours ago and
> want to do something useful now :-)
> I have a hash and I want to iterate trough all pairs of values. An example:
> 
> h = {"john" => 41, "mary" => 31, "fred" => 10}
> #insert control structure here
>      age=(h[person1]+h[person2]).to_s
>        puts "#person1 shakes hands with #person2. Together they are #age
> years old"
>        
>   
> The output could for example be:
> 
> john shakes hands with mary. Together they are 72 years old
> john shakes hands with fred. Together they are 51 years old
> mary shakes hands with fred. Together they are 41 years old
> 
> 
> what I do at the moment:
> 
> h = {"john" => 41, "mary" => 31, "fred" => 10}
> h.each_key{|person1| 
>   h.each_key{|person2| 
>     if h.sort.index([person1,h[person1]])<h.sort.index([person2,h[person2]])
>      age=(h[person1]+h[person2]).to_s
>        puts "#{person1} shakes hands with #{person2}. Together they are
> #{age} years old"
>     end }}
> 
> Is there a more elegant way to do this? 
> 
> TIA,
>  Kevin
> 


-- 
Brian Schr�der
http://www.brian-schroeder.de/