'tschuldige, da ist was verrutscht:
Delphi-Quellcode:
procedure TForm1.btn1Click(Sender: TObject);
var
i, j: Integer;
s: string;
begin
s := '';
for i := 0 to 3 do
begin
for j := 0 to 9 do
begin
mmo1.Lines.Add(s + IntToStr(j));
end;
s := s + '0';
end;
end;