Interfaces cannot be instantiated— they can only be implemented by classes or extended by other interfaces.
Interface in JavaInterfaces cannot be instantiated, but rather are implemented. A class that implements an interface must implement all of the methods described in the interface, or be an abstract class.
Abstraction in Java"If a class is abstract and cannot be instantiated, the class does not have much use unless it is subclassed." A parent class contains the common functionality of a collection of child classes, but the parent class itself is too abstract to be used on its own.
DDD (Deadly Diamond of Death)Java doesn't support multiple inheritance because of Deadly Diamond of Death(DDD). What it is ?? Here is an example--
Multilevel Inheritance in Java"Cow Class" calling methods that are available inside classes "Herbivore & Animal". Though "Cow" extends only class "Herbivore", it would in turn inherit the properties of "Animal" extended by "Herbivore" .
InheritanceBase classes(child class) can inherit attributes and behavior from pre-existing classes (superclasses, parent classes) Single level inheritanceMultiple Inheritance is not allowed in JavaJava doesn't support multiple inheritance because of Deadly Diamond of Death(DDD).
PolymorphismPolymorphism is the ability of an object to take on many forms. The most common use of polymorphism in OOP occurs when a parent class reference is used to refer to a child class object.
First Java Program. Its easy. Follow the steps..
|