From: Len Lawrence <lcl@...>
Date: 2009-06-14T02:20:07+09:00
Subject: Re: Last element skip in array mapping

On Sat, 13 Jun 2009 09:52:17 -0700, Matt Neuburg wrote:

> Len Lawrence <lcl@tarazed.demon.co.uk> wrote:
> 
>> Still a newbie after 2 years, investigating obscure corners of the
>> language (version 1.8).  I made some tests based on a discussion in
>> _why's "bits" RedHanded blog:
>> 
>> a = [ 1, 2, 3, 4, 5, nil ]
>> b = [ 1, 2, 3, 4, 5 ]
>> x = a.map { |k| k.to_s }.join( "0\n" ) puts x
>> 
>> s = a.map { |k| k }.join( "0\n" )
>> puts s
>> 
>> z = a.to_a.join( "00\n" )
>> puts z
>> 
>> beep = b * "000\n"
>> puts beep
>> 
>> Unless the dummy element is added to the array (as in a) the series
>> does not complete for any of the mapping methods.  Am I missing
>> something here?
> 
> Consider:
> 
> puts [1].join("0")
> puts [1, nil].join("0")
> 
> m.

Thanks.  Back to the documentation.
Misunderstanding - thought join meant adding the argument string to the 
array element.  I see that the argument is a separator between elements.
Duh!  Easy to miss these things at my age (70).

Len