Another thing that is well worth knowing about is "closures". This is where a function (or even better a group of functions) share a variable that is hidden from everything else.

So you could do something like: 

# These brackets limit the scope of the lexical variables
  {
    # So this is a global variable that can only be seen 
    # between here and the close bracket below
    my(%parts);

    sub register_table
      {
        my($part_name,$part) = @_;

        $parts{$part_name} = $part;
      }

    sub get_table
      {
        my($part_name) = @_;

        return($parts{$part_name});
      }
  }

# So out here we can call &register_table and
# &get_table but we cannot see %parts

[download]

OK so this is a rather simplistic explination of what a closure does. It is good enough for a first level of understanding and there are lots of much better explinations on the web if you are interested

In reply to Re: Tk::Notebook and scope by hawtin
in thread Tk::Notebook and scope by Soko

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