From: James Edward Gray II <james@...>
Date: 2006-04-10T23:38:37+09:00
Subject: Re: Beginner array manipulation questions

On Apr 10, 2006, at 9:26 AM, Jamal Mazrui wrote:

> Suppose the variable path is an array of fully qualified path and file
> names (e.g., in Windows, an item might be "c:\folder\file.txt").  What
> would be an efficient way of creating another array that contained  
> only
> the file extensions (one or more characters following the last .
> character, if any)?  I know I could use a while loop and a counter,  
> but
> figure there is a better way in Ruby.

 >> files = %w{c:\folder\file1.txt c:\folder\file2.exe c:\folder 
\file3.pdf} => ["c:\\folder\\file1.txt", "c:\\folder\\file2.exe", "c:\ 
\folder\\file3.pdf"]
 >> files.map { |f| File.extname(f) }
=> [".txt", ".exe", ".pdf"]

> Alternatively, how could I change the array so that it was two
> dimensional where each "row" had two "columns" consisting of the full
> name and the extension only?

 >> files.map { |f| e = File.extname(f); [f[0..(-1 - e.length)], e] }
=> [["c:\\folder\\file1", ".txt"], ["c:\\folder\\file2", ".exe"], ["c: 
\\folder\\file3", ".pdf"]]

Hope that helps.

James Edward Gray II