From: "David A. Black" <dblack@...>
Date: 2007-11-04T05:28:48+09:00
Subject: Re: x=[]; x[:bla][:some_key] does not work?

Hi --

On Sun, 4 Nov 2007, Joshua Muheim wrote:

> Hi all
>
> PHP lets me easily create multidimensional hashes using the following
> syntax:
>
> x = array();
> x["bla"]["some_key"] = true;
>
> Is Ruby not capable of doing this?
>
> x = []
> x[:bla][:some_key] = true
>
> gives me a nil error!

Are you sure it's not giving you a "Symbol as array index" error?

> What wrong here?

A couple of things. You're indexing an array with a symbol, but you
have to use an integer. You're also expecting a non-existent array
element to be something other than nil, but it isn't:

   a = []
   a[1]    # nil

You're then trying (or would be, if you used an integer instead of
:bla) to call the method [] on nil, and nil has no such method.
(Remember that the index syntax, a[n], is actually a method call:
a.[](n).)


David

-- 
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