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