From: "Christopher Özbek" <newsgroups@...>
Date: 2002-03-27T06:07:45+09:00
Subject: Re: yield in iterator's body -

>
> This ...
>
> ["H", "A", "L"].collect { |x| x.succ }.each{|b|
>       puts "I got #{b}"
>  }
>
> .. produces
>
> I got I
> I got B
> I got M

Collect changes an array by replacing each entry by the result of the code
block and returns this new array (collect! changes inplace). So

["H", "A", "L"].collect { |x| x.succ }

returns

["I", "B", "M"]


> However, this ...
>
> ["H", "A", "L"].each { |x| x.succ }.each{|b|
>       puts "I got #{b}"
>  }
>
> . gives:
>
> I got H
> I got A
> I got L
>
> So, my question is, what exactly is the difference between 'each' and
> 'collect'?

each just executes the code block for each element once. Neither is the
array changed (collect!) nor is a new one returned (collect).

> Why doesn't the 'each' block return the value of the last expression?

The value of the last expression would be "M" in this case, would it? I
don't know, this is maybe just because in most cases the programmer needs
the array more than the result from the last call.

  Christopher :)