Inheritance of Object Class in Java

Question

While i was reading java book, i came across "Every class extends class Object"...but if want a class B to extend class A.....but Class B will be now having multiple inheritance,one from Object class and one from Class A.How the conflict is resolved. Can anyone explain?

Answer 1

Its multi-level inheritance, not multiple:

class A extends Object

class B extends A

Answer 2

First of all, Object class is the super/base/parent class of every class including user-defined classes.

So even if we don't mention it explicitly, the user-defined classes extends Object class by default.

Morevoer, Object class implements a set of methods and variables which are common to all the objects being created in the application. This is the main reason why we have Object class as a base class for all the other classes.

For eg:

hashCode() - this method creates a unique identity for each of the object being created in JVM.