You have a number of errors interacting to result in your bug. The closest code to that you posted that functions is: 

#!/usr/bin/perl -w
use warnings;

sub printElement(\%$)
{
   my $hash_ref = $_[0];
   my $key = $_[1];
   print $key." ".$hash_ref->{$key}."\n";
}

my %hash = (0 => 'a', 1 => 'b', 2 => 'c');
while(($key) = each(%hash))
{
   printElement(%hash, $key);
}

[download]

A large fraction of your problem can be traced back to incorrect use of Prototypes. For one thing, note that by using the & you are disabling the prototype. As well, if you hadn't disabled the prototype, passing in a hash reference would violate the prototype. In the end, your real problem is that using %hash in list context results in resetting the iterator in each. This is one of the reasons many people favor keys for the kind of loop you are describing.

As a side note, consider using strict: see Use strict warnings and diagnostics or die.

In reply to Re: subroutine reference parameters by kennethk
in thread subroutine reference parameters by dnajjar

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.