Abstract Class Header Java

It is used to exchange the functionality between the concrete class members and the abstract class.

Abstract class header java. A class that is declared using abstract keyword is known as abstract class. The abstract keyword is a non access modifier used for classes and methods. Abstract classes are considered as those classes that hide the method implementation details from the user and show only the method functionality. An example of an abstract class in the jdk is abstractmap which is part of the collections framework.

Java abstract classes and methods data abstraction is the process of hiding certain details and showing only essential information to the user. By dinesh thakur category. It can have abstract and non abstract methods method with the body. For example abstract class reader has concrete subclasses bufferedreader stringreader inputstreamreader etc.

An abstract class is distinguishable from other classes by the fact that it is not possible to use the new operator to construct objects from them directly. Each abstract class may have at least zero abstract methods. Youll find abstract classes are named something abstract and concrete subclasses are named something more concrete. Abstract classes in java act as a boundary between the implementation method and its functionality.

A concrete class completely implements all its methods whereas an abstract class can have abstract methods and concrete methods. Unlike concrete classes abstract classes cannot be instantiated. Inheritance an abstract class is one whose header contains the reserved keyword abstract. Abstraction can be achieved with either abstract classes or interfaces which you will learn more about in the next chapter.

A normal class non abstract class cannot have abstract methods. The default class is a concrete class it doesnt use any additional keyword whereas an abstract class is declared using keyword abstract. Before learning the java abstract class lets understand the abstraction in java first.