如何初始化一个对象成员？

Question

type
       TGroup=class(TcollectionItem)
   private
    FGroupID: string;
    FGroupName: string;
    FMajorGrade: TMajorGrade;
   public
      property GroupID:string ;
      property GroupName:string ;
      property MajorGrade:TMajorGrade ;      
end;
var thegroup:Tgroup;
在程序中我要给对象成员Majorgrade的majorgradeid属性付值，应该怎么办，是否要
首先初始化majorgrade?  如何初始化。

Answer 1

在TGroup 中重载constuctor函数，对变量赋值

Answer 2

TGroup=class(TcollectionItem)
 public                     { constructors are always public }
    constructor Create(AOwner: TComponent); override; { this syntax is always the same }
  end;
...
constructor TGroup.Create(AOwner: TComponent);     { this goes after implementation }
begin
  inherited Create(AOwner);                           { ALWAYS do this first! }
  FMajorGrade:=;//这里进行操作end;