Wieso funktioniert das hier mit OUT?

[Bummi]

versuch mal das ...

Delphi-Quellcode:

procedure Test(out xy: String);
begin
  ShowMessage(xy);
end;


procedure Test2(var xy: String);
begin
  ShowMessage(xy);
end;

procedure TForm4.Button1Click(Sender: TObject);
const
  C_S= 'Schau mal da';
var
 s:String;
begin
  s := C_S ;
  Test(s);
  Test2(s);


  s := C_S;
  Test(s);
  s := C_S;
  Test2(s);
  s := C_S;

end;