From: Paul Roche <prpaulroche@...>
Date: 2010-10-25T03:10:18+09:00
Subject: Re: Utilizing data from a csv file

Jeremy Bopp wrote in post #956736:
> On 10/24/2010 09:34 AM, Paul Roche wrote:
>> ----------------------------------------------
>>
>> end
>>
>> end
>>
>> -------------------------------------------
>>
>> Here is a rough idea I have so far, but it's returning nothing
>>
>> songs = []
>>
>> songs.each {|song| songs << Song.new(song.name, song.owner)}
>
> This rightly does nothing.  The each method operates over the array
> itself by calling the given block with each of the array elements in
> turn.  In this case, songs is an empty array because you set it as such
> just before calling songs.each, so there are no elements for the each
> method to process.
>
> You seem to have a small gap in your understanding of how variables are
> assigned values here.  When you set songs to [], you have lost the value
> passed in as the songs argument of the build_all method.  Do you see
> what I mean?
>
> Try something even simpler:
>
> def make_array(items)
>   new_items = []
>   items.each { |item| new_items << (item * 10) }
>   new_items
> end
>
> these_items = [1, 2, 3, 4]
> those_items = make_array(these_items)
>
>
> After running this, what are the values of these_items and those_items?
>  How does that change if you replace "new_items" with "items" everywhere
> in the make_array function?  Why do you think that happens?  From where
> is the value of "item" acquired in the make_array function?  What
> happens if you change these_items as follows:
>
> these_items = ['1', '2', '3', '4']
>
>
> -Jeremy

Thanks Jermey, this example has helped. This did the trick......

def self.build_all(songs)

new_items = []
  songs.each { |item| new_items << Song.new(item.name, item.owner) }
   new_items

end

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