长字串与宽字串

procedure TForm1.Button1Click(Sender: TObject);
var
  s1: AnsiString;  //单字节储存
  s2: WideString;  //双字节储存
begin
  s1 := '万一OK';
  s2 := '万一OK';

  ShowMessage(s1[1]);  //显示乱码
  ShowMessage(s2[1]);  //万

  ShowMessage(IntToStr(Length(s1)));  //6
  ShowMessage(IntToStr(Length(s2)));  //4

  ShowMessage(IntToStr(SizeOf(s1)));  //4
  ShowMessage(IntToStr(SizeOf(s2)));  //4, 其 SizeOf 的大小相同，因为它们只是个指针地址
end;