Joao Morais wrote 32 lines
Damien Gerard wrote:
>
> On Jan 21, 2008, at 2:52 PM, Joao Morais wrote:
>
>> Damien Gerard wrote:
>>> I have (it would seem) a stupid question :)
>>> We have TStringList vars. User can do what he want with it.
>>> Which one is the stupid or the better way to do it ?
>>> TMyClass = class(TObject)
>>> public
>>> <snip>
>>> List1: TStringList;
>>> List2: TStringList;
>>> end;
>>> or
>>> TMyClass = class
>>> private
>>> FList1: TStringList;
>>> FList2: TStringList;
>>> public
>>> property List1: TStringList read FList1;
>>> property List2: TStringList read FList2;
>>> end;
>>
>> The later, *much* better. You should never use class members outside
>> the private area.
>
> Thanks ! What is the reason ? I am happy I was right but I need some
> reason :)
Encapsulation, on behalf of the integrity of the instance.
Implementation detail is also a good example. Then:
TMyClass = class
private
FList1: array of string; //convoluted, but uses a different storage
mechanism
FList2: array of string;
protected
function GetList1: TStringList; virtual;
function GetList1: TStringList; virtual;
public
property List1: TStringList read GetList1;
property List2: TStringList read GetList2;
end;
You can implement the storage for GetList1 and GetList 2 any way that you wish internally, but give a uniform external interface.
