How to count number of rows in a cursor

create or replace function f_row_count_objects return number is
cursor c_var01 is select * from HieuPV;
rt_var02 c_var01%ROWTYPE;
var03 number;
begin
    open c_var01;
    if c_var01%ISOPEN then
    loop
        fetch c_var01 into rt_var02;
        exit when c_var01%NOTFOUND;
   end loop;
    end if;
    var03:= c_var01%ROWCOUNT;
    close c_var01;
    return var03;
end;
/
select f_row_count_objects() from dual;