%customer = (
    fname => 'John',
    lname => 'Doe',
    phone => undef,
);

##</code><code>##

sub thing {
    my $string = shift;
    my ($f0, $f1, $f2, $f3, $f4, $f5) = split /|/, $string;
    $f2 = $f4 + 5;
    return ($f0, $f2, $f3);
}

##</code><code>##

sub thing {
    my $string = shift;
    my ($f0, $f1, $f2, $f3, $f4, $f5) = split /|/, $string;
    $f2 = $f4 + 5;
    return ($f0, $f1, $f2, $f3);
}

##</code><code>##

sub thing {
    my $string = shift;
    my @f = split /|/, $string;
    $f[2] = $f[4] + 5;
    return @f;
}