5.2 Fields

Object Fields are like record ﬁelds. They are accessed in the same way as a record ﬁeld would be accessed : by using a qualiﬁed identiﬁer. Given the following declaration:

Type TAnObject = Object
       AField : Longint;
       Procedure AMethod;
       end;
Var AnObject : TAnObject;

then the following would be a valid assignment:

AnObject.AField := 0;

Inside methods, ﬁelds can be accessed using the short identiﬁer:

Procedure TAnObject.AMethod;
begin
  ...
  AField := 0;
  ...
end;

Or, one can use the self identiﬁer. The self identiﬁer refers to the current instance of the object:

Procedure TAnObject.AMethod;
begin
  ...
  Self.AField := 0;
  ...
end;

One cannot access ﬁelds that are in a private section of an object from outside the objects’ methods. If this is attempted anyway, the compiler will complain about an unknown identiﬁer. It is also possible to use the with statement with an object instance:

With AnObject do
  begin
  Afield := 12;
  AMethod;
  end;

In this example, between the begin and end, it is as if AnObject was prepended to the Afield and Amethod identiﬁers. More about this in section 9.2.7, page 338

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