If you wanted to avoid using a hash of named arguments for whatever reason, but wanted to avoid typing 
my $argN="default";
$argN=shift if @_;

[download]
repeatedly, perhaps the following would be useful :
&foo (1,2,3);

sub foo {
    my @defaults= qw (foo bar baz quux quuz boo);
    for (1.. @_) {shift @defaults};
    @_= (@_, @defaults);
    ($a1, $a2, $a3, $a4, $a5, $a6) = @_;    
    print join "\n",$a1, $a2, $a3, $a4, $a5, $a6;
}

[download]
This doesn't check that a user's supplied too many parameters, but that shouldn't be too hard to add in.
Of course, as mentioned elsewhere, this is all moot once // comes into play, but it's an interesting mental exercise.

An additional note : this assumes that parameters are given in "least optional" to "most optional"; if you have 6 params and only #2 is optional, this won't do it for you.

In reply to Re: (3) Explicitly check for argument presence... (boo) by boo_radley
in thread Default subroutine parameters by thelenm

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.