Why Object is Super Class in Java

Question

1. All Java classes extend java.lang.Object
2. All Java classes cannot extend itself

I wanted to know then how come Object is the superclass for itself?

Answer 1

Object is an exception to the first rule, and has no superclass. From JLS3 8.1.4:

The extends clause must not appear in the definition of the class Object, because it is the primordial class and has no direct superclass.