Esteemed Monks,

I understand that undef() and hashes are not meant for each other. That said, I was wondering if anyone could specifically explain the wierdness occurring when you run the following piece of code. 
#! /usr/bin/perl 

use strict ;
use warnings ;

local $\ = "\n" ; # some formatting
my %h ;
print ( defined %h ? "Defined!" : "Undefined!" );

undef( %h ) ;
print ( defined %h ? "Defined!" : "Undefined!" );

%h = undef ;
print ( defined %h ? "Defined!" : "Undefined!" );

undef( %h ) ;
print ( defined %h ? "Defined!" : "Undefined!" );

#OUTPUT
#Undefined!
#Undefined!
#Defined!
#Undefined!

[download]

It seems to me that the hash is undefined until you try to assign something to it, and it doesn't matter what that something is. Also, I'm confused as to why, in this case, using undef as a function actually performs the undefine on the hash.

Peace monks,

Update:
I've followed advice and added use warnings and use strict (this started as a perl -e that was being passed around my office). We've also used Data::Dumper on it, just for play.
Bro. Doug :wq

In reply to hash assignment wierdness by Bro. Doug

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.