Program menentukan Bilangan Prima dengan Delphi

unit Unit1;

interface

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

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

var
  Form1: TForm1;

implementation

{$R *.dfm}


procedure TForm1.Button1Click(Sender: TObject);
var a,b : integer;
hasil : String;
begin
a:=StrToInt(Edit1.Text);
if a = 2 then hasil:='Bilangan Prima'
else if a < 2 then hasil:='Bukan Bilangan Prima'
else
begin
for b:=2 to a-1 do
begin
if a mod b = 0 then
begin
hasil:='Bukan Bilangan Prima';
break;
end
else hasil:='Bilangan Prima';
end;
end;
ShowMessage(hasil);
end;
end.

Desain form :