From: Nelson Owen <nowen@...55.com>
Date: 2005-09-08T04:38:49+09:00
Subject: weird result when updating an array element

Given the code below, only one element in @ver should be changed, 
however when I execute the code all the elements are changed. Can anyone 
explain why this is happening?

class SomeClass
    def initialize
        @ver  = Array.new(2, {'pos' => Array.new(3), 'col' => Array.new(4)})
        @ver[0]['pos'][0] = 0
        puts @ver.inspect
    end
end
SomeClass.new

actual result:
[{"col"=>[nil, nil, nil, nil], "pos"=>[0, nil, nil]}, {"col"=>[nil, nil, 
nil, nil], "pos"=>[0, nil, nil]}]

expected result:
[{"col"=>[nil, nil, nil, nil], "pos"=>[0, nil, nil]}, {"col"=>[nil, nil, 
nil, nil], "pos"=>[nil, nil, nil]}]