创建儿子班以扩展父亲班

// 来自 NowJava.com

class Father

{

    int age;


    public void setage()

    {

        age = 75;

    }


    public int getage()

    {

        return age;

    }

}


class Son extends Father
/*
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 时 代 J a v a 公 众 号 - nowjava.com
*/

{

    int S_age;


    public void setage_S()

    {

        S_age = 45;

    }


    public int getage_S()

    {

        return S_age;

    }

}


class GrandSon extends Son

{

    int GS_age;


    public void setage_GS()

    {

        GS_age = 15;

    }


    public int getage_GS()

    {

        return GS_age;

    }

}


class Multi_Level

{

    public static void main(String args[])

    {

        GrandSon obj = new GrandSon();


        obj.setage();

      obj.setage_S();

      obj.setage_GS();


        System