Originally posted by rama murthy: I didn't understand.
I'm afraid I don't understand your question, either.
In Java, when an object is created, its constructor is always called. Every constructor calls the direct superclass's constructor, and so on, up until Object's constructor is called. This way, every object, including the parts inherited from some other class, can be initialized.
So, are you asking why this is so, or are you saying (for some reason that's unclear to me) that you think Object should be a special case, and its constructor should be skipped?
Because every class may need a chance to initialize its member variables; this is done in the constructor. Therefore the constructor of each parent class is called, so that any inherited member variables may be initialized.