From: Phillip Gawlowski <cmdjackryan@...>
Date: 2008-04-09T11:33:13+09:00
Subject: Re: output of a method to file?

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Zoe Phoenix wrote:
| I think I understand what you're saying, but I'm not quite sure how to
| apply it...

Let me show you an example:

irb(main):001:0> array = ["a","b","c","d","e"]
=> ["a", "b", "c", "d", "e"]
irb(main):002:0> array.each_with_index do |item, index|
irb(main):003:1* puts item if index % 3 == 0
irb(main):004:1> end
a
d
=> ["a", "b", "c", "d", "e"]

In this example, only the elements at an index that can be divided by 3
without a problem are printed. You can achieve a similar effect with a
counter, for example.

(My idea to use modulo was a bit off, sorry about that).

Translated to your problem:
saving.rb:

c_list = [
~    'Boston',
~    'Nashville',
~    'San Francisco',
~    'Houston',
~    'Portland',
~    'Atlanta',
~    'Chicago',
~    'Indianapolis',
~    'Charleston'
~    ]

counter = 1
temp_array = []
c_list.each_with_index do |item,index|
~  temp_array.push "|| " if index % 3 == 0
~  temp_array.push "#{item} "
~  temp_array.push "pets ||"
~  temp_array.push "\n" if counter % 3 == 0
~  counter +=1
end
puts 'File completed. Save as..?'
save_as = gets.chomp


File.open("c:/rubyfiles/citylist-#{save_as}.txt","w") do |f|
~  f.write temp_array
end

What am I doing here (this is a very naive implementation, nothing
fancy, but it does what it is supposed to do)?

First, I create the array of cities (you can get fancy later on, and
read it from a file, too).

Then, I create a counter to help me later on, as well as an empty array.

After that, I iterate over the c_list array with the help of the
each_with_index method.

Now the fun starts:


temp_array.push "|| " if index % 3 == 0

This only gets done, in the case that I can divide the index by 3
without a remainder. This works with 0, so I get the "|| " part.


temp_array.push "#{item} "

This uses Ruby's String interpolation to create, for example, "Boston ".
String interpolation allows you to execute Ruby code within Strings,
roughly speaking. You can test that by doing puts "#{Time.now}" in irb,
for example.


temp_array.push "\n" if counter % 3 == 0

This pushes the newline character into the array for file output, in the
case that the counter variable I introduced earlier can be divided by 3
without a remainder.

This should give you at least a starting point, in case I missed what
you wanted.

File block you already know. :)

HTH,
- --
Phillip Gawlowski
Twitter: twitter.com/cynicalryan

~ - You know you've been hacking too long when...
...you begin to think in nested IF-THEN-ELSE clauses that would make a
bureaucrat get lost.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.8 (MingW32)
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org

iEYEARECAAYFAkf8Ku8ACgkQbtAgaoJTgL+wMwCdEFdqJL6WyzUsNvZWTBjjc8Hh
cqEAn2xcrv7D4uUwuMyc8GwvtptoYdbG
=c3il
-----END PGP SIGNATURE-----