unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    Button1: TButton;
    Edit1: TEdit;
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
    function Test(var aaa : Integer): boolean;
  end;

var
  Form1: TForm1;

implementation

{$R *.DFM}

procedure TForm1.Button1Click(Sender: TObject);
var
  aaa : integer;
begin
  test(aaa);
  Edit1.Text := inttostr(aaa);
end;

function TForm1.Test(var aaa : Integer): boolean;
begin
  aaa := 100;
end;

end.

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