java中的继承

（1）比较好理解的

class Fu {
    int num1 = 5;
}

class Zi extends Fu {
    int num2 = 4;
}

public class zihefu {

    public static void main(String[] args) {
        Zi z = new Zi();
        System.out.println(z.num1 + "....." + z.num2);

    }

}

（2）比较能理解的

class Fu {
    int num = 5;
}

class Zi extends Fu {
    int num = 4;
}

public class zihefu {

    public static void main(String[] args) {
        Zi z = new Zi();
        System.out.println(z.num + "....." + z.num);

    }

}

（3）this

class Fu {
    int num = 5;
}

class Zi extends Fu {
    int num = 4;
    void show(){
        System.out.println(this.num);//注意看这,子类的方法
    }
}

public class zihefu {

    public static void main(String[] args) {
        Zi z = new Zi();
        z.show();
        System.out.println(z.num + "....." + z.num);

    }
}

（4）super

class Fu {
    int num = 5;
}

class Zi extends Fu {
    int num = 4;
    void show(){
        System.out.println(super.num);//注意看这,子类的方法
    }
}

public class zihefu {

    public static void main(String[] args) {
        Zi z = new Zi();
        z.show();
        System.out.println(z.num + "....." + z.num);

    }
}