public class MobilPhoneTest {
    public static void main(String[]args){
        MobilPhone mp=new MobilPhone();
        mp.brand="苹果";                         //发工资了，修改品牌属性
        String detail=mp.buy("发工资了"); //发工资了，调用带参数的构造方法
        System.out.println(detail);
    }
}