Why does every object in Java implicitly extend java.lang.Object class?

Question

I have been programming in Java for quite some time, but when I tried to explain what an java.lang.Object class is to a friend, I could not come up with more th

Answer 1

Every Class extends Object class implicitly so that they provide basic features which according to Java recommendation every class should have. Such as clone(), equals(), hashCode(), toString(), etc.

By implicitly, it means that if you are not extending any class then only compiler will implicitly extends Object class.But if class already extends other class then compiler will not extend Object class. For eg. Class A{ }

Class B extends A{ }

Here compiler will implicitly add extends Object class in class A declaration.

Class A extends Object{ }

Class B extends A{ }

As class A extends Object class so it will provide basic functionality of Object class such as equals(), toString(),etc. And since Class B extends class A which implicitly extends Class Object, so class B also provides all those features.

Thus by following this approach every class objects(variables) complies to features which every Java Object should have, without going for Multiple Inheritance (a class extending more than one class) which Java doesn't allows. This approach follows Multi-Level Inheritance.