Delphi 使用SetLength后的猜想验证

unit Unit2;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls;

type
  TForm2 = class(TForm)
    btn1: TButton;
    procedure btn1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;
  
var
  Form2: TForm2;

implementation

{$R *.dfm}
type
tsubjects = record
  chinese:string[255];
  mathematics:string[255];
  english:string[255];
end;
ptstudents = ^tstudents;
 tstudents = record
   id:Integer;
   scores: array of tsubjects;
 end;
 var
 pstudents:ptstudents = nil;
procedure TForm2.btn1Click(Sender: TObject);
begin
  New(pstudents);
  SetLength(pstudents.scores, 100000);

  SetLength(pstudents.scores, 0);
end;

end.

　　在开发邮件的过程中，有考虑系统邮件占用大量内存，结构体里使用了动态数组，排查内存泄露，

以上测试程序得知，setlength内部实现了 自动的内存管理申请和释放