type
 TTestInstructionDataType = (
   TIDT_INT,
   TIDT_FLOAT,
   TIDT_BOOL
 );
  TForm1 = class(TForm)
     Label1: TLabel;
     Button1: TButton;
     procedure Button1Click(Sender: TObject);
  private
  public
  end;
var
  Form1: TForm1;
implementation

procedure TForm1.Button1Click(Sender: TObject);      
var i : integer;
begin           
 i := 1;

//(a)
 case i of
   TIDT_INT : Label1.Caption := '1' ;
   TIDT_FLOAT : Label1.Caption := '2' ;
   TIDT_BOOL : Label1.Caption := '3' ;
 end;  

//(b)
 case i of
   0 : Label1.Caption := '1' ;
   1 : Label1.Caption := '2' ;
   2 : Label1.Caption := '3' ;
 end;
end;

end.