procedure TForm1.FormCreate(Sender: TObject);
var
  S: string;
  StringList: TStringList;
begin
  StringList := TStringList.Create;
  try
    StringList.Add ( 'Hello1' );
    StringList.Add ( 'Hello2' );
    StringList.Add ( 'Hello3' );
    StringList.Add ( 'Hello4' );
    StringList.Delimiter := ';';
    S := StringList.DelimitedText;
    ShowMessage(S);
  finally
    StringList.Free;
  end;
end;