I would like to know the difference between "%$foo{'bar'}" and "$foo->{'bar'}". To be more specific, I would like to know why and in what instance each form can be used correctly. I have a theory why, but I would like confirmation.

My theory is that the first method needs to have $foo contain the scalar that is that name of a hash that needs to be referenced because that scalar name is looked up in the variable table...
i.e,: 

%my_hash  = {};
$hash_ref = 'my_hash';
%$hash_ref{'foo'} = 'bar'; #sets %my_hash{'foo'} = 'bar'

[download]

So I think the above would work. The difference between the two scenarios is the type of reference. The arrow operator needs to have a reference that points to memory and a value in the variable table.

Is my logic correct? If not, please correct me, but if I am right, at least one person confirm it so I can move on to some more Perl enlightenment.

Thank you.
the_Don

In reply to Using $foo->{'bar'} and not %$foo{'bar'} by the_Don

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • 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! —
  • 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:
    & &amp;
    < &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.