If you don't mind some memory hungry list processing code ... Update: urk, misread the op's question, so here's code that actually makes sense 
use DDS; # aka Data::Dump::Streamer

my %self = {};
$self->{foo}     = [ 1, 2, 3 ];
$self->{bar}     = [ 4, 5, 3 ];
$self->{nerd}    = [ 3, 4, 8 ];
$self->{geek}    = 1;
$self->{useless} = 1;

my @sets   = map  {{ map{$_=>undef} @$_ }}
             grep { 'ARRAY' eq ref } values %$self;
my @uniq   = grep {
  my $el = $_;
  @sets == grep { exists $_->{$el} } @sets;
} map keys(%$_), @sets;

Dump \@uniq;

[download]
HTH

_________
broquaint

In reply to Re: how do i find common elements of X number of arrays whose names i don't know? by broquaint
in thread how do i find common elements of X number of arrays whose names i don't know? by basscakes

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.