sub convert_to_float {
        my ( $number ) = @_;
        $number = sprintf '%.02f', $number || 0;
        $number =~ s/.(\d*[1-9])?0*\z/,$1/;
        return $number;
}
convert_to_float(1);
__END__
Use of uninitialized value $1 in concatenation (.) or string