Inheritance

When encapsulation is the first mechanism in Object Oriented Programming, the second fundamental Object Oriented mechanism is inheritance. This allows descendants of a class to inherit all of its member elements and methods from its ancestors as well as creates its own. These descendants are known as subclasses. A classes immediate parent is called its super class. In Java, a special key word extends is used to implement this mechanism. Following is the example to illustrate this.

Write a program in Java to implement inheritance.
import java.util.*;

class Student {
    String Name;
    int rno;
    Scanner s=new Scanner(System.in);
    void getdata() {
        System.out.println("Enter The Name Of Student ->");
        Name=s.nextLine();
        System.out.println("Enter The Roll No Of Student ->");
        rno=s.nextInt();
    }
}
class Marks extends Student {
    int cs;
    int math;
    int ele;
    int tot;
    int avg;
    void getmarks() {
        System.out.println("Enter The Marks For CS ,MATH And  Ele Subjects ->");
        cs=s.nextInt();
        math=s.nextInt();
        ele=s.nextInt();
    }
    void caltot() {
        tot=cs+ele+math;
        avg=tot/3;
    }
    void puttot() {
        System.out.println("The Total Of Marks Of Student Is ="+tot);
        System.out.println("The Average Of Marks Of Student Is ="+avg);
    }
}
class SimpleInheritance {
    public static void main(String[] args) {
        Marks m=new Marks();
        m.getdata();
        m.getmarks();
        m.caltot();
        m.puttot();
    }
}

Output
Enter The Name Of Student ->
sneha
Enter The Roll No Of Student ->
45
Enter The Marks For CS ,MATH And  Ele Subjects ->
85
71
62
The Total Of Marks Of Student Is =218
The Average Of Marks Of Student Is =72