From: Stefano Crocco <stefano.crocco@...>
Date: 2010-07-13T17:56:29+09:00
Subject: Re: I'm trying to get the keys, but why values appear?

On Tuesday 13 July 2010, Abder-rahman Ali wrote:
> |I'm trying to write a script that lists ONLY the keys in a hash as
> |follows: http://pastie.org/private/1ruahb5w05ihsloqwmqeng
> |
> |The case is that when I run the script, I get the following:
> |
> |NameAbder-Rahman Ali
> |Age26
> |
> |While, I'm intending to get
> |
> |Name
> |Age
> |
> |What am I missing in the script?
> |
> |Thanks.

As you can see from the documentation (for example, with ri Hash#each), 
Hash#each yields two arguments to the block: the key and the corresponding 
value. Since your block only takes one argument, ruby puts both in an array, 
whose to_s method produces a string with the two elements one after the other.

If you only want the key, you can use each_key rather than each, since this 
will only pass the block the keys:

personal_information.each_key{|k| puts k}

If you want to use each (but you don't need to in your example), you can have 
the block take two parameters and only use the first (the key):

personal_information.each{|key, val| puts key}

or have the block take a single argument (which will be an array) and use only 
the first entry of the array

personal_information.each{|i| puts i[0]}

I hope this helps

Stefano