From: Joel VanderWerf <vjoel@...>
Date: 2001-12-31T11:51:50+09:00
Subject: [ruby-talk:29787] Re: Ruby multi-dimensional Hash question?

"Crandall, Jeff W" wrote:
> 
> Ruby Guru's:
> 
> I want to dynamically(while reading data in from a file) create a
> multi-dimensional hash array.  Something like the following:
> 
> myHash[a1[<index_number>][a2[index_number>] = a3[<index_number>]

One way (
kinda crude, but simple), is:

(h[a1[index]] ||= {})[a2[index]] = ...

The ||= effectively means "assign if left side is nil".

There are fancier ways, like PerlValue:

http://www.ruby-lang.org/en/raa-list.rhtml?name=PerlValue