Prakash Dahagam wrote:My question is that if My class(Say Abcd) extends some other class, and how it is possible to extend Object class to Abcd .
The root class doesn't have to be a direct super class. There could be many classes in the hierarchy between a given class and
Object.
You can compare it to a family tree. If
class A extends Object and
class B extends A, then you can see class
A as class
B's father and
Object as its grandfather.
and what is the root interface of all interfaces ?
There is no such thing. Interfaces have a less structured hierarchy. There is extension, but one interface can extend multiple other interfaces.