{
    my @FIELDS = qw( foo bar baz );
    sub set_params 
    {
        use CGI qw(:standard);
        map { $_ => param($_) || '' } @FIELDS;
    }
}

# Other subroutines here 

{
    my %params = set_params();
    # Call other subroutines here 
}

##</code><code>##

{
    my @FIELDS = qw( foo bar baz );
    sub new 
    {
        my $class = shift;
        my $in    = shift || { };  # Passed in a hashref
        my %self  = map { $_ => $in->{$_} || '' } @FIELDS;
        bless \%self, $class;
    }
}