Java Object superclass

Question

I have a weird Java question:

As we know:

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

Answer 1

You'd be better off thinking of this as:

1. All java classes must implement the interface implied by the methods in java.lang.Object.
2. The concrete class java.lang.Object provides default implementations of these functions.
3. All other java classes are derived from the object java.lang.Object and may choose to use or override the default implementations of the methods.

The two main points are: all the classes must implement the implied interface and the Java language spec gives you (forces upon you?) default implementations for these methods for free.