Pass by reference - this is what I usually do: 
my @array = qw(a b c d e f);
my @new_array = do_something(\@array); #<- note the "\"

sub do_something {
  my $array_ref = shift;
  my @new = ();
  foreach (@{$array_ref}) { #<- treat the ref as an array
    # do some stuff like build @new
  }
  return @new;
}

[download]
You can also return ref's which means you can return mulitiple array, hash, and scalar references by using as a list with out them getting all flattened out together.

To give you a visual of what an array looks like versus an array reference, Data::Dumper would show:

For '@array' outside the subroutine: 
$VAR1 = a
$VAR2 = b
..etc

[download]
For '$array_ref' inside the subroutine: 
$VAR1 = [a,b,c,d,e,f]

[download]
This is because $array_ref points to an anonymous array passed to to the subroutine while @array IS the array.

In reply to Re: passing arrays to subroutines by perlfan
in thread passing arrays to subroutines by Anonymous Monk

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.