What is the difference between extends and override?

Question

What is the difference between

extends(inheritance)

and

override(polymorphism)

?

Answer 1

Extends: we create a new class(Inherited class) with the features of Existing (class Base class) and some additional features. This comes in picture in case of inheritance.

Example: NokiaBasic Handset. NokiaNSeries(Extends the features of NokiaBasic Handset features)

Overriding: comes to picture when functionality changes in the derived class. We override the functionality of a particular function in a derived class(Dynamic Polymorphism).

Example: All the functionality which NokiaBasicHandset has, are implemented in NokiaNSeries but there is a difference in the way we operate. (Picking a call, sending a message, sharing a file, etc.)

Answer 2

• Extends is about classes. This keyword represents the process of deriving a subclass from a base class.
• Overriding is about methods declaration and invocation. It means to define a method in a subclass with the same signature of a method previously declared in its base class.