From: Alex Stahl <astahl@...5.com>
Date: 2010-09-23T04:33:26+09:00
Subject: Odd behavior when << hash

Hi Folks - Using Ruby 1.8.7, I found this oddity:

require 'rubygems'
require 'json'

setup = []
ids = ["12345", "54321", "21345", "548752", "3215", "50203"]

doIt = {
  "action" => "do something",
  "result" => "true"
}

cnt = rand(10)
1.upto(cnt) do

  doIt['params'] = ids[rand(6)]
  p "Pushing step: #{doIt.inspect}"
  setup << doIt
end

p "Final steps list: #{setup.inspect}"

**************************************

When I inspect my final steps list at the end, the values of
'doIt['params']' is always the same - set to the last value of the last
run of the upto loop.  But when I inspect doIt prior to pushing it, I
can see that it has its own value, acquired randomly.  

So my question is, why is the hash not being pushed onto the array
properly?  What side effect am I encountering here and how do I get
around it?

(I've already tried declaring "params" => "" in the initial hash
creation; that didn't help).

Thanks,
Alex

PS - You'd be correct in noting this code doesn't do anything useful.
I've stripped away other parts to isolate the questionable behavior for
demonstration purposes.