No, not really. That only works if $1 happens to be undefined. Which you can't count on. Watch: 
#!/usr/bin/perl

use strict;
use warnings;

"meep" =~ /(.*)/;  # Set $1.

my $address1 = "Tsjakka";  # Will match.
my $address2 = "Tsjakka!"; # Will not match.


{
    $address1 =~ /^([A-Za-z0-9öäåÖÄÅ][A-Za-zöäåÖÄÅ0-9\s\-\.\,]*)$/;
    $address1 = $1;
}
{
    $address2 =~ /^([A-Za-z0-9öäåÖÄÅ][A-Za-zöäåÖÄÅ0-9\s\-\.\,]*)$/;
    $address2 = $1;
}

print $address1, "\n";
print $address2, "\n";

__END__
Tsjakka
meep

[download]
$address2 doesn't become undef. The solution is much simpler. The regex will either match the entire string, or there's no match. So, we could just do: 
/^([A-Za-z0-9öäåÖÄÅ][A-Za-zöäåÖÄÅ0-9\s\-\.\,]*)$/ 
          or $_ = undef for $address1, $address2;

[download]

Abigail

In reply to Re: $1 don't reset (non loop) by Abigail-II
in thread $1 don't reset (non loop) by jockel

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.