delphi中自定义的类 应该写在什么位置 谢谢

一般情况下
uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs;

type
a = array of integer;//这里
TForm1 = class(TForm)
private
{ Private declarations }
public
{ Public declarations }
end;
type
tmystring = string;//或者这里
var
Form1: TForm1;

implementation