程序代码：

do
    {
    cout << "1-------显示所有" << endl;
    cout << "2-------添加信息" << endl;
    cout << "3-------查询信息" << endl;
    cout << "4-------修改信息" << endl;
    cout << "请选择功能：";
    cin >> number;
    switch (number)
    {
    case 1:
        sony.show_all() ;
        lenovo.show_all() ;
        break;
    case 2:
        add(sign);
        break;
    case 3:
        menu2();
        break;
    }
    }while(number == 10);