As opposed to what? arrays and hashes? You can't pass those to subroutines. You can only pass a list of scalars to a subroutine. If you have an array or a hash in your parameter list, it gets flattened into a list of its elements. Sometimes, one can recreate the array or hash from that list. But while the whole concept of flattening an array or a hash then creating a new array or hash is pretty icky, the real problem is that often one cannot recreate the original variables. 
sub f {
    my (@a,%h) = @_;
    print("The array has ", 0+@a, " elements\n");
    print("The hash has ", 0+keys(%h), " elements\n");
}

my @a = qw( a b c );
my %h = ( d=>4, e=>5, f=>6 );
f(@a,%h); # Same as f($a[0],$a[1],$a[2],'e',$h{e},'d',$h{d},'f',$h{f})

[download]
The array has 9 elements
The hash has 0 elements

[download]

Since one often has to use references, it's not a bad idea to default to passing a reference. At least, that's the reason I do it. It gets confusing if you're not consistent.

In reply to Re: Array or Hash Reference to Subroutine by ikegami
in thread How to use @EXPORT by pkperl

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.