Memo1内容：

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unit Unit2;

interface

uses

  Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,

  Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls;

type

  TForm2 = class(TForm)

    Memo1: TMemo;

    Memo2: TMemo;

    Button1: TButton;

    procedure Button1Click(Sender: TObject);

  private

    { Private declarations }

  public

    { Public declarations }

  end;

var

  Form2: TForm2;

implementation

{$R *.dfm}

procedure TForm2.Button1Click(Sender: TObject);

var

  I: Integer;

begin

for I := 0 to Memo1.Lines.Count-1 do

begin

if (strtoint(Memo1.Lines.Strings[i])>=5) and (strtoint(Memo1.Lines.Strings[i])<=8) then

begin

  Memo2.Lines.Add(Memo1.Lines.Strings[i]);

end;

end;

end;

end.

结果：

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