Comments on your OO page, some nit-picky:

• Explain references first. Starting with OO and then saying, oh, they're just references, won't help. References are difficult. Perhaps make them an entirely separate lesson (and remember, complex references usually turn out to be the most useful
• Explain why a hash reference is a good idea for an object. Why not an array ref? Are other references options? (yes, but discuss why we usually pick hashes).
• You have to be more careful of case. For example you've written both this:

  my $pp=new ball("Ping-Pong");
  [download]

  and this: the scalars $PP
• Your very first new sub has no comments but is far from intuitive. Perhaps something more like:

  package ball;  # things from here will be of the ball class
  
      # Makes a new ball object.
  sub new {
                  # assign all my parameters
          my ($class, $name, $size) = @_;
         
          my $self = {};  # This will be our new object
  
                # Mark this hash ref as a "ball" object
          bless $self, $class;                   
  
                # do our initialization (add useful defaults)
          $self->{'name'} = $name || "unnamed";
          $self->{'size'} = $size || 0;   
          return $self;
  }
  [download]

  is in order.
• Your second new function is even more unwieldy. Comment and perhaps focus on shift less. (It might not be necessary if you use something like mine above)
• All your subs below your second new function are out of alignment.

I think that there's a lot that you're taking for granted about OO and Perl OO. As this is a draft that's fine, but you need to explain more. pjf and I do Perl training courses that cover both references and Perl OO. Feel free to read over our course notes and see if there's anything there that can help you. http://www.perltraining.com.au/notes/

I hope this helps.

jarich

---

---

Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!

Titles consisting of a single word are discouraged, and in most cases are disallowed outright.

Read Where should I post X? if you're not absolutely sure you're posting in the right place.

Please read these before you post! —

• How do I compose an effective node title?
• How do I post a question effectively?
• Markup in the Monastery

Posts may use any of the Perl Monks Approved HTML tags:

a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr

You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)

	For:		Use:
	&		&
	<		&lt;
	>		&gt;
	[		&#91;
	]		&#93;

Link using PerlMonks shortcuts! What shortcuts can I use for linking?

See Writeup Formatting Tips and other pages linked from there for more info.