Best way to find some value from OBJECT TYPE TABLE

create or replace TYPE r_type  FORCE AS RECORD
                   (
      Code NUMBER(15),
      Description NUMBER(15));


create or replace procedure t1 as
      TYPE tr_type IS TABLE OF r_type;
      tr_type_i tr_type;
begin
      r_type(1).code := '1';
      r_type(1).description := 't1';

      r_type(2).code := '1';
      r_type(2).description := 't1';

      r_type(3).code := '1';
      r_type(3).description := 't1';
end;

If I want to search for code 4 in r_type.code column as is it exist or not .

What is the best way to do that

Thanks and Regards