From: Christophe Grandsire <christophe.grandsire@...>
Date: 2005-10-28T13:42:50+09:00
Subject: Re: difference between the each iterator and the collect iterator?

Selon vasten@gmail.com :
> Hi:
> I am a newbie as far as Ruby is concerned. I was going through the
> programming ruby book (2nd Edition), but was not able to figure out the
> difference between the 2 statements:
> 
> [1, 2, 3, 4].collect{[i] puts i }
> and
> [1, 2, 3, 4].each{|i| puts i }
> 
> Can some guru in this group shed some light?
> 
> Thanks.
> 
> 

#collect applies the block on each value of the array, and *returns the 
result of the expression as an array for each value*. #each applies the 
block on each value of the array, but *returns the unmodified array*. 
#collect is used for the effect it has on the array, #each is just used 
for looping.

You can't see the difference here because you are not catching the array 
returned by #collect. Usually one would do:
result = [1,2,3,4].collect{|i| do_something(i)}
while leaving #each the way you did it.
-- 
Christophe Grandsire.

http://rainbow.conlang.free.fr

You need a straight mind to invent a twisted conlang.