When you pass a hash, it is passed as a list, so everything you are passing to the subroutine is ending up in %URLS, leaving $title empty (and perl would warn you of this, by telling you that an odd number of elements had been assigned to a hash, if you were using -w). To avoid the problem you either have to pass scalars first, and put the list at the end, or pass lists by reference.

To pass by reference you can either do it explicitly:

printurls(\%URLS,$title);
sub printurls {
    my($urls,$title) = @_;
    my %URLS = %{$url};
}

[download]

Or, you can use prototypes, to make them references for you:

printurls(%URLS,$title);
sub printurls(%$) {
    my($urls,$title) = @_;
    my %URLS = %{$urls};
}

[download]

In reply to Re: Hash of Lists Subroutine Problem by jasonk
in thread Hash of Lists Subroutine Problem by gohaku

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.