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unit Unit1; interface uses Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, Dialogs, StdCtrls; type TForm1 = class(TForm) Button1: TButton; Button2: TButton; procedure FormCreate(Sender: TObject); procedure Button1Click(Sender: TObject); procedure Button2Click(Sender: TObject); end; var Form1: TForm1; implementation {$R *.dfm} type PMyRec = ^MyRec; {把 PMyRec 定义为下面 MyRec 结构的指针类型} MyRec = record Name: string[8]; Age : Word; Link: PMyRec; {结构中同时包含同类型的指针, 用于链接其他同类结构} end; var R1,R2,R3,R4: MyRec; {把 R1、R2、R3、R4 够建成一个环环相扣的"链", 这就是一个简单的"链表"} procedure TForm1.FormCreate(Sender: TObject); begin R4.Name := '李四'; R4.Age := 16; R4.Link := nil; R3.Name := '张三'; R3.Age := 61; R3.Link := @R4; R2.Name := '钱二'; R2.Age := 24; R2.Link := @R3; R1.Name := '赵一'; R1.Age := 42; R1.Link := @R2; end; {现在 , 通过 R1 即可以访问整个链; 但这个链是单向的, 所以叫"单向链表"} procedure TForm1.Button1Click(Sender: TObject); begin ShowMessage(R1.Name); {赵一} ShowMessage(R1.Link^.Name); {钱二} ShowMessage(R1.Link^.Link^.Name); {张三} ShowMessage(R1.Link^.Link^.Link^.Name); {李四} end; {通过结构指针读取数据可以省略 ^; 所以 Button1Click 可以简写为:} procedure TForm1.Button2Click(Sender: TObject); begin ShowMessage(R1.Name); {赵一} ShowMessage(R1.Link.Name); {钱二} ShowMessage(R1.Link.Link.Name); {张三} ShowMessage(R1.Link.Link.Link.Name); {李四} end; end. |
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