A neat trick that may, or may not, help (depending on what you are trying to achieve) is to generate a bit vector:

use strict;
use warnings;

my $name = '';
my $vorname = 'full';
my $plz = 1;
my $tel = 0;
my $tel49 = undef;

my $vector = (!$name) || 2;
$vector |= (!$vorname) || 4;
$vector |= (!$plz) || 8;
$vector |= (!$tel) || 16;
$vector |= (!$tel49) || 32;

printf "%06b\n", $vector;

[download]

which sets a bit in $vector for each "true" variable. As a bonus it sets the least significant bit if any of the variables is false. Note BTW that there is a big difference between defined and "true". The sample prints:

001101

[download]
DWIM is Perl's answer to Gödel

In reply to Re: A Case with 5 Var's by GrandFather
in thread A Case with 5 Var's by ultibuzz

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.