From: Siep Korteling <s.korteling@...>
Date: 2008-09-22T06:36:24+09:00
Subject: Re: Iterating through a string

Ruby Fan wrote:
> Stefano Crocco wrote:
>> Alle Sunday 21 September 2008, Jody Glidden ha scritto:
>>> If I try the following...
>>>
>>> "I love guitar playing".split {|s| s.capitalize}.join(" ")
>>>
>>> I would expect it to capitalize the first letter of each word but it
>>> doesn't seem to work.
>>>
>>> Any hints on what I'm doing incorrectly?
>> 
>> 
>> String#split doesn't take a block, so that the block you pass to it is
>> ignored. What you wrote is equivalent to
>> 
>> "I love guitar playing".split.join(" ")
>> 
>> To do what you want, you need to call map on the array returned by
>> String#split:
>> 
>> "I love guitar playing".split.map{|s| s.capitalize}.join(" ")
>> 
>> I hope this helps
>> 
>> Stefano
> 
> Ahh, I understand.  I must have missed the map/collect functionality.
> 
> Thanks.

"I love guitar playing".split.each{|s| s.capitalize}.join(" ")

does not work because #capitalize does not modify the original; it gives 
you a copy. Map/collect really collects these copies, #each does not. 
However

"I love guitar playing".split.each{|s| s.capitalize!}.join(" ")

Does work, because the self-modifying #capitalize! is available. 
Personally I'm starting to prefer #map , also because of this:

a = (1..9).map{|n| n*n}

#versus my old way

a = [] #annoying
(1..9).each{|n| a<<n*n}

Regards,

Siep
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