javaclassobjectmethodsname-hiding

How do I access Super class variables and methods in main method?


    class Main
{
    public static void main(String[] arg)
    {
        C c = new C();

        c.show(); //how to access class A
    }

}

class A
{
    void show()
    {
    System.out.println("inside A");
    }
}

class B extends A
{
    void show()
    {
        System.out.println("inside B");
    }
}

class C extends B
{
    void show()
    {
        super.show(); //How to access class A
        System.out.println("inside C");
    }
}

Using super I can access Super Class variables and methods like C can access B's methods but what if I want to access A's methods in C. How do I do that in simple way like using super? Like two super should do the trick... And how do I access Class A method only by allocating Class C(if name-hiding present)?


Solution

  • There is no construct in Java to do something like c.super.super.show() as it violates encapsulation. The Law of Demeter is a good principle illustrating why this is rightly avoided. Taking this into account, the way you can do what you request within Java is to expose a.show() in b like this:

    class Main
    {
        public static void main(String[] arg)
        {
            C c = new C();
    
            c.show(); //how to access class A
        }
    
    }
    
    class A
    {
        void show()
        {
            System.out.println("inside A");
        }
    }
    
    class B extends A
    {
        void show()
        {
            System.out.println("inside B");
        }
    
        void showA()
        {
            super.show();
        }
    }
    
    class C extends B
    {
        void show()
        {
            super.showA(); // Calls A
            System.out.println("inside C");
        }
    }