From: Henry Maddocks <hmaddocks@...>
Date: 2012-10-15T06:09:45+09:00
Subject: Re: how to join the return of array


On 15/10/2012, at 10:04 AM, Ruby Mania <lists@ruby-forum.com> wrote:

> Thanks a bunch !
>  This works like a charm but just curious why I have to initialize and 
> I could not just do
> 
>  out[symb] << hq.close
> 
>  without initialise

Because the default value of an uninitialised hash key is nil and nil doesn't respond to <<


>> out = {}
=> {}
>> out['foo']
=> nil
>> out['foo'] << 'bar'
NoMethodError: undefined method `<<' for nil:NilClass
	from (irb):3
	from /Users/henry/.rbenv/versions/1.9.3-p125/bin/irb:12:in `<main>'
>> 


Henry