SimpleInheritance.java

package chapter8;

class A {
    int i, j;

    void showij() {
        System.out.println("i and j " + i + " " + j);
    }
}

class B extends A {
    int k;

    void showk() {
        System.out.println("k = " + k);
    }

    void sum() {
        System.out.println(" i + j + k : " + (i + j + k));
    }
}

public class SimpleInheritance {
    public static void main(String[] args) {

        A superOb = new A();
        B subOb = new B();

        //The superclass may be used by itself
        superOb.i = 10;
        superOb.j = 20;
        System.out.println("Contents of superOb : ");
        superOb.showij();
        System.out.println();

        //The subclass has access to all members of its superclass
        subOb.i = 7;
        subOb.j = 8;
        subOb.k = 9;

        System.out.println("Contents of subOb : ");
        subOb.showij();
        subOb.showk();
        System.out.println();

        System.out.println("Sum of i , j  and k in subOb : ");
        subOb.sum();
    }

}