上转型对象成员方法与变量的访问特点

public class Fu {
    int a = 100;
    void miner(){
        a--;
    }
    int getA(){
        return a;
    }
}


 class Zi extends Fu {
    int a = 0;
    void miner(){
        a++;
    }
    int getA(){
        return a;
    }
}

public class Test {
    public static void main(String[] args) {
        Fu x = new Zi();
        System.out.println(x.a);
        System.out.println(x.getA());
        x.miner();
        System.out.println(x.a);
        System.out.println(x.getA());
    }
}

运行结果：