From: wys@... (Clemens Wyss)
Date: 2001-04-06T15:10:04+09:00
Subject: [ruby-talk:13527] Re: Newbie Question

ts <decoux@moulon.inra.fr> wrote in
<200104051449.f35EnUN21222@orsay1.moulon.inra.fr>: 

>
> First you assign the string '10' to h['1'], then you index this string
> with '2' and replace the content (if it found) with '10'
>
<< SNIP >>
> In you case '2' was not found in '10' and ruby has not modified the
> hash, 

I would have expected that Ruby raised an error here!
Smalltalk has the following methods:
   at: <key> put: <value>       	    	    	    
which would raise an exception if the key/index does not exist. The
"exception handling variant": 
   at: <key> put: <value> ifAbsent: <a block>
would execute the block if the key/index is not valid.
These methods apply for Arrays (String etc.) and Hashes (Dictionary).

Clemens