From: Daniel Schierbeck <daniel.schierbeck@...>
Date: 2006-07-28T18:35:09+09:00
Subject: Re: Creating hashes with duplicate keys

Sy Ali wrote:
> I want to simplify this hash creation:
> g = { 1 => "test", 2 => "test", }
> 
> I have a particularly complicated hash that I'm generating.  It can
> have very large values.
> 
> Right now, I duplicate values with something like this:
> 
> c = { 1 => "one", }
> d = { 2 => c[1], }
> c.merge!(d)
> 
> however, I don't like the way my code looks.. I want to be able to
> specify the duplication within the hash generation.
> 
> Is this possible?

This will work:

   hsh = Hash.new{|h, k| h[k] = (k == 1 ? "one" : h[k - 1])}

Note that all the values will be the same -- the same object! If you 
want duplicates, do this instead:

   hsh = Hash.new{|h, k| h[k] = (k == 1 ? "one" : h[k - 1].dup)}

Just ask if there are parts of the snippet you don't understand.


Cheers,
Daniel