From: Ryan Leavengood <mrcode@...>
Date: 2005-06-27T07:39:27+09:00
Subject: Re: newbie scope question

Charles L. Snyder wrote:
> 
> Why does this not work?

Because the variable doc is local to the top-level scope and can't be 
seen inside the methods of Crap. This works:

$doc = File::open("my.txt")
class Crap
   def junko
     @doc = $doc
     @doc.each {|line| print line}
   end
end
myobj=Crap.new
myobj.junko
$doc.close

$doc is now a global. Of course, I would not recommend coding this way. 
For example your original code never closed the file (which is probably 
not that bad here because at exit open files will be closed.) In 
addition globals are bad in most cases.

Using File::open with a block, and passing in the file (like your second 
example) is better:

class Crap
   def junko(doc)
     @doc = doc
     @doc.each {|line| print line}
   end
end

File::open("my.txt") do |file|
   myobj=Crap.new
   myobj.junko(file)
end

That way the file is closed automatically when the block ends.

Ryan