1个子界的例子

 1 unit Unit1;
 2 interface
 3 uses
 4   Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
 5   Dialogs, StdCtrls;
 6 type
 7   TForm1 = class(TForm)
 8     Button1: TButton;
 9     procedure Button1Click(Sender: TObject);
10   private
11     { Private declarations }
12   public
13     { Public declarations }
14   end;
15 var
16   Form1: TForm1;
17 implementation
18 {$R *.dfm}
19 var
20 i:integer;
21 procedure TForm1.Button1Click(Sender: TObject);
22 begin
23  i:=9;
24  if i in [1..7] then  //子界表达式
25  showmessage('i<=7')
26  else
27  showmessage('9不在这个子界里面');
28 end;
29 end.
30