Pointer Question...

[rcloutie]

Hi all,

I read about pointers since few days and found that Delphi's objects (or class's instances) are already pointers.
Knowing that, I have simple question...

Do pointers are important when speaking objects or they are only when dealing with types or records definition)?

Is that class definition valid ?

type MyClass: TMyClass
  MyParent: ^TMyClass;
end;

or should be replaced with ?

type MyClass: TMyClass
  MyParent: TMyClass;
end;

In the second definition, is MyParent takes twice the memory or once with two pointers?

Thanks for help,

Rej Cloutier

 

[whosrdaddy]

your first class version of myparent is nothing more than a pointer to a typed TMyclass pointer, so both are valid, though I think it is the second version you want to use. (Untyped) Pointers are really old style (c) and should be avoided as there not really OOP.

concerning the memory question : the variable itself will consume 4 bytes (32bit pointer) if Myparent points to a valid class (use MyClass := TMyClass.Create) then the class will also consume memory.

/Daddy

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[rcloutie]

Thanks.
It's always nice to get things confirmed by someone else.
Have a nice day.

RC