From: Todd Benson <caduceass@...>
Date: 2008-02-21T10:39:31+09:00
Subject: Re: displaying user inputed arrays

On Wed, Feb 20, 2008 at 5:36 PM, Isaac Toothyxdip <toothyxdip@gmail.com> wrote:
> Thanks that really shortens up my code and works but i have a couple
>  questions
>
>
>
>
>  a, n = nil
>  puts "Please enter 5 words"
>  until (a = (gets.scan /[\w'-]*/) - [""]).length == 5
>   puts "Please type in exactly FIVE words, thanks."
>  end
>  puts "You would like to print out which word number? (1-5)"
>  until (1..5).include? (n = gets.chomp.to_i)
>   puts "Please pick a number 1 through 5"
>  end
>  puts a[n - 1]
>
>  i under stand almost all of it (i just dont get what the - [""] does and

Try [1, 2, 3, 4] - [1, 4] to understand the methodology, - [""]
removes empty strings created by scan because /[\w'-]/ is not only
greedy, but _zero_or_more_, which means it will return empty strings
for characters you don't include (like spaces).

>  i think that means that it puts it into an array but the main questions
>  i have are why did you type a, n = nil that isnt needed

You're right.  It isn't necessary.  I thought it might be for scope reasons.

> and also why did
>  you type /[\w'-]*/) when /\w+/ works the same ... i think

Yep, you're right accept you won't need the - [""] with /[\w'-]+/
because you won't get empty strings in the array with _one_or_more_ of
those characters (the + instead of the *).

I sort of tried to get that across with my last post.

I'm not saying the last code I posted (with +, not *, and without the
- [""]) is the best, but I like it because it sort of makes
grammatical sense.

cheers,
Todd