From: Igor Sutton Lopes <igor.sutton@...>
Date: 2007-06-29T09:43:35+09:00
Subject: Re: newby non/programmer trying to understand classes

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On Jun 28, 2007, at 9:16 PM, Rob Biedenharn wrote:

>
> Basically.  If you just had:
>
>   names = Hash.new
>
> then referencing non-existent keys gives nil, but they still do not  
> exist.
>
>   names['joe'] << 'hello'
>
> would give an error trying to call nil.<<('hello')
>
> By assigning to h[k], that key is created in the 'names' hash with  
> the indicated value (an empty Array in this case).
>
> It's about the same as:
>
>  names = Hash.new    # or just names = {}
>  (names['joe'] ||= []) << 'hello'
>

Thanks for your explanation!


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