[solve] Object inside a class

[cappe]

With this example

  ca = class
  public
    type

    { r }

    r = object

      procedure Esegui;
    end;
  public
    c : String;
    rec :r;
  end;

procedure ca.r.Esegui;
begin
 
  How can I access here the variable c of the class ca

end;   

What I would like to know is how can I access the procedure  ca.r.Esegui to the variable c of the class ca?
Thanks

[Otto]

Ciao

It depends on what you want to achieve.
Dipende da ciò che vuoi ottenere.

(Ho dedotto che tu conosca l'italiano ma potrei sbagliarmi).

[cappe]

Scrivo in inglese

procedure ca.r.Esegui;
begin
 
  How can I access here the variable c of the class ca?
 
  I want to access the variable "c" (string) of the "ca" class which contains "r"

end;   

[marcov]

Pass a reference to the class to the objects. Nested symbols (classes,objects,records) don't automatically have access to their parent reference.

[Thaddy]

Example program:

Code: Pascal  [Select][+][-]

1. {$mode objfpc}
2. type
3.   TMyClass = class
4.   private
5.     Type
6.       TmyObject = object
7.       public
8.         procedure doIt;
9.       end;
10.   public
11.     procedure DoIt;
12.   end;
13.  
14.   procedure TMyClass.TMyObject.DoIt;
15.   begin
16.     writeln('DoIt from nested object');
17.   end;
18.  
19.   procedure TMyClass.DoIt;
20.   var
21.     d:TMyObject;  
22.   begin
23.     d.DoIt;
24.   end;
25.    
26. var
27.   c:TMyClass;
28. begin
29.   c:=TMyClass.Create;
30.   try
31.     c.doit;
32.   finally
33.     c.free;
34.   end;
35. end.

But indeed, Marco's answer is correct. The example is merely to illustrate the parent class can use variables from the child object, so you can also move that variable to the object instead.

[bytebites]

Code: Pascal  [Select][+][-]

1. type
2.  
3.   { ca }
4.  
5.   ca = class
6.   public
7.     type
8.  
9.     { r }
10.  
11.     r = object
12.       parent: ca;
13.       procedure Esegui;
14.     end;
15.   public
16.     c: string;
17.     rec: r;
18.     constructor Create;
19.   end;
20.  
21.   { ca }
22.  
23.   constructor ca.Create;
24.   begin
25.     rec.parent := self;
26.   end;
27.  
28.   procedure ca.r.Esegui;
29.   begin
30.     //How can I access here the variable c of the class ca
31.     writeln(parent.c);
32.   end;
33.  
34. var
35.   ci: ca;
36. begin
37.   ci:=ca.create;
38.   ci.c:='Hello';
39.   ci.rec.Esegui;
40. end.                                  
41.  

[Thaddy]

That is what Marco referred.

[cappe]

Nice idea.

Thank you all.

Code: Pascal  [Select][+][-]

1. type
2.  
3.   { ca }
4.  
5.   ca = class
6.   public
7.     type
8.  
9.     { r }
10.  
11.     r = object
12.       parent: ca;
13.       procedure Esegui;
14.     end;
15.   public
16.     c: string;
17.     rec: r;
18.     constructor Create;
19.   end;
20.  
21.   { ca }
22.  
23.   constructor ca.Create;
24.   begin
25.     rec.parent := self;
26.   end;
27.  
28.   procedure ca.r.Esegui;
29.   begin
30.     //How can I access here the variable c of the class ca
31.     writeln(parent.c);
32.   end;
33.  
34. var
35.   ci: ca;
36. begin
37.   ci:=ca.create;
38.   ci.c:='Hello';
39.   ci.rec.Esegui;
40. end.                                  
41.