From: Joel VanderWerf <vjoel@...>
Date: 2003-10-04T12:14:05+09:00
Subject: Re: hash of hashes

Dave Brown wrote:
> In article <200310031434.31907.argentoff@rtelekom.ru>,
> Paul Argentoff  <argentoff@rtelekom.ru> wrote:
> : On Friday 03 October 2003 14:04, Paul Argentoff wrote:
> : 
> : > How can I create $Subject for future population?
> : 
> : Let's put it this way: I need to create a nested hash which will be populated 
> : later by referencing the keys in the subhashes. How can I do this?
> 
> You mean, er,
> 
> irb(main):001:0> a=Hash.new({})
> => {}
> irb(main):002:0> a['foo'] 
> => {}
> 
> ?
> 
> --Dave

That's like, a real bad trip, dude:

irb(main):002:0> a=Hash.new({})
=> {}
irb(main):003:0> a[1]
=> {}
irb(main):004:0> a[1]["x"] = "y"
=> "y"
irb(main):005:0> a
=> {}
irb(main):006:0> a[1]
=> {"x"=>"y"}
irb(main):007:0> a[1] = 2
=> 2
irb(main):008:0> a[2]
=> {"x"=>"y"}
irb(main):009:0> a[1]
=> 2

It would help to do

a = Hash.new {{}}

since you get a new hash each time...