The document discusses abstract classes and interfaces in Java. It defines abstract classes as classes that cannot be instantiated but can be sub-classed, and may contain abstract methods without implementations. Interfaces are defined to specify what a class must do without defining how, and allow for multiple inheritance in Java by implementing multiple interfaces. The document provides examples of defining abstract classes and interfaces, extending abstract classes, implementing interfaces, and comparing interfaces to abstract classes.
What are Abstract Classes in Java | EdurekaEdureka!
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This Edureka PPT on Abstract Classes in Java will provide you with detailed knowledge about Abstract Classes in Java and along with it, This PPT will also cover some examples of Abstract Classes in Java, in order to provide you with a deep understanding about their functionality. This PPT will cover the following topics:
What are Abstract Classes in Java?
Why do we need an Abstract Classes in Java?
Rules for using Abstract Classes in Java
Ways to achieve Abstraction in Java
The Syntax for Abstract Classes
Practical Examples of Abstract Classes
Difference between Interface and Abstract Class
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What are Abstract Classes in Java | EdurekaEdureka!
YouTube Link: https://youtu.be/5X0Y--92pMI
**Java, J2EE & SOA Certification Training - https://www.edureka.co/java-j2ee-training-course **
This Edureka PPT on Abstract Classes in Java will provide you with detailed knowledge about Abstract Classes in Java and along with it, This PPT will also cover some examples of Abstract Classes in Java, in order to provide you with a deep understanding about their functionality. This PPT will cover the following topics:
What are Abstract Classes in Java?
Why do we need an Abstract Classes in Java?
Rules for using Abstract Classes in Java
Ways to achieve Abstraction in Java
The Syntax for Abstract Classes
Practical Examples of Abstract Classes
Difference between Interface and Abstract Class
Complete Java Playlist: http://bit.ly/2XcYNH5
Complete Blog Series: http://bit.ly/2YoabkT
Follow us to never miss an update in the future.
YouTube: https://www.youtube.com/user/edurekaIN
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An abstract class is a class that is declared abstract —it may or may not include abstract methods. Abstract classes cannot be instantiated, but they can be subclassed. When an abstract class is subclassed, the subclass usually provides implementations for all of the abstract methods in its parent class.
Interface in java By Dheeraj Kumar Singhdheeraj_cse
In Java,
An interface is a way through which unrelated objects use to interact with one another.
Using interface, you can specify what a class must do, but not how it does it.
It is not a class but a set of requirements for classes that implement the interface.
Java OOP Programming language (Part 6) - Abstract Class & InterfaceOUM SAOKOSAL
Java OOP Programming language (Part 6) - Abstract Class & Interface
Oum Saokosal
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An interface is a reference type in Java. It is similar to the class. It is a collection of abstract methods. A class implements an interface, thereby inheriting the abstract methods of the interface. Along with abstract methods, an interface may also contain constants, default methods, static methods, and nested types.
Interface in java ,multiple inheritance in java, interface implementationHoneyChintal
multiple inheritance in java, interface implementation, abstraction,
multiple inheritance in java using interface, how to use interface,
how to use java, how to execute a java code
Abstraction is a process by which concepts are derived from the usage and classification of literal ("real" or "concrete") concepts.
Abstraction is a concept that acts as a super-categorical noun for all subordinate concepts, and connects any related concepts as a group, field, or category.
UNEP year book 2012 | Emerging issues in our global enviromentBTO Educational
United Nations Environment Programme
The 2012 UNEP Year Book spotlights two emerging issues that underline the challenges but also the choices nations need to consider to deliver a sustainable 21st century— urgently improved management of the world’s soils and the decommissioning of nuclear reactors.
An abstract class is a class that is declared abstract —it may or may not include abstract methods. Abstract classes cannot be instantiated, but they can be subclassed. When an abstract class is subclassed, the subclass usually provides implementations for all of the abstract methods in its parent class.
Interface in java By Dheeraj Kumar Singhdheeraj_cse
In Java,
An interface is a way through which unrelated objects use to interact with one another.
Using interface, you can specify what a class must do, but not how it does it.
It is not a class but a set of requirements for classes that implement the interface.
Java OOP Programming language (Part 6) - Abstract Class & InterfaceOUM SAOKOSAL
Java OOP Programming language (Part 6) - Abstract Class & Interface
Oum Saokosal
Where to me find me more:
YouTube: https://www.youtube.com/user/oumsaokosal
FB Page: https://facebook.com/kosalgeek
PPT: https://www.slideshare.net/oumsaokosal
Twitter: https://twitter.com/okosal
Web: http://kosalgeek.com
An interface is a reference type in Java. It is similar to the class. It is a collection of abstract methods. A class implements an interface, thereby inheriting the abstract methods of the interface. Along with abstract methods, an interface may also contain constants, default methods, static methods, and nested types.
Interface in java ,multiple inheritance in java, interface implementationHoneyChintal
multiple inheritance in java, interface implementation, abstraction,
multiple inheritance in java using interface, how to use interface,
how to use java, how to execute a java code
Abstraction is a process by which concepts are derived from the usage and classification of literal ("real" or "concrete") concepts.
Abstraction is a concept that acts as a super-categorical noun for all subordinate concepts, and connects any related concepts as a group, field, or category.
UNEP year book 2012 | Emerging issues in our global enviromentBTO Educational
United Nations Environment Programme
The 2012 UNEP Year Book spotlights two emerging issues that underline the challenges but also the choices nations need to consider to deliver a sustainable 21st century— urgently improved management of the world’s soils and the decommissioning of nuclear reactors.
How SME's Can Become Sustainability Leadersarchana cks
Growing economic pressures, an uncertain political landscape and increasing competition means sustainability has in some cases fallen down the business agenda.
Source <> http://www.bizbilla.com/articles/How-SME-s-can-become-sustainability-leaders-1766.html
Star Link Communication Pvt. Ltd., India's leading manufacturer of biometric attendance system and access control system, brings you this slideshow about biometrics and how the technology works.
Hầu hết những người sở hữu một kết nối Internet hiện đại ngày nay đều phải sử dụng đến kỹ thuật NAT (Network Address Translation). NAT đã là một phần không thể thiếu khi triển khai mạng IP diện rộng do không gian địa chỉ IPv4 đã bắt đầu co hẹp. Về cơ bản, NAT cho phép một (hay nhiều) địa chỉ IP nội miền được ánh xạ với một (hay nhiều) địa chỉ IP ngoại miền. Điều này cho phép sử dụng dải địa chỉ IP riêng theo chuẩn RFC 1918 trên các mạng nội bộ trong khi chỉ sử dụng một hoặc một số ít các địa chỉ IP công cộng. Bài viết sẽ trình bày những khái niệm cơ bản về NAT, các loại NAT và cách thức hoạt động của công nghệ này.
Unit 8 - Information and Communication Technology (Paper I).pdfThiyagu K
This slides describes the basic concepts of ICT, basics of Email, Emerging Technology and Digital Initiatives in Education. This presentations aligns with the UGC Paper I syllabus.
The Roman Empire A Historical Colossus.pdfkaushalkr1407
The Roman Empire, a vast and enduring power, stands as one of history's most remarkable civilizations, leaving an indelible imprint on the world. It emerged from the Roman Republic, transitioning into an imperial powerhouse under the leadership of Augustus Caesar in 27 BCE. This transformation marked the beginning of an era defined by unprecedented territorial expansion, architectural marvels, and profound cultural influence.
The empire's roots lie in the city of Rome, founded, according to legend, by Romulus in 753 BCE. Over centuries, Rome evolved from a small settlement to a formidable republic, characterized by a complex political system with elected officials and checks on power. However, internal strife, class conflicts, and military ambitions paved the way for the end of the Republic. Julius Caesar’s dictatorship and subsequent assassination in 44 BCE created a power vacuum, leading to a civil war. Octavian, later Augustus, emerged victorious, heralding the Roman Empire’s birth.
Under Augustus, the empire experienced the Pax Romana, a 200-year period of relative peace and stability. Augustus reformed the military, established efficient administrative systems, and initiated grand construction projects. The empire's borders expanded, encompassing territories from Britain to Egypt and from Spain to the Euphrates. Roman legions, renowned for their discipline and engineering prowess, secured and maintained these vast territories, building roads, fortifications, and cities that facilitated control and integration.
The Roman Empire’s society was hierarchical, with a rigid class system. At the top were the patricians, wealthy elites who held significant political power. Below them were the plebeians, free citizens with limited political influence, and the vast numbers of slaves who formed the backbone of the economy. The family unit was central, governed by the paterfamilias, the male head who held absolute authority.
Culturally, the Romans were eclectic, absorbing and adapting elements from the civilizations they encountered, particularly the Greeks. Roman art, literature, and philosophy reflected this synthesis, creating a rich cultural tapestry. Latin, the Roman language, became the lingua franca of the Western world, influencing numerous modern languages.
Roman architecture and engineering achievements were monumental. They perfected the arch, vault, and dome, constructing enduring structures like the Colosseum, Pantheon, and aqueducts. These engineering marvels not only showcased Roman ingenuity but also served practical purposes, from public entertainment to water supply.
June 3, 2024 Anti-Semitism Letter Sent to MIT President Kornbluth and MIT Cor...Levi Shapiro
Letter from the Congress of the United States regarding Anti-Semitism sent June 3rd to MIT President Sally Kornbluth, MIT Corp Chair, Mark Gorenberg
Dear Dr. Kornbluth and Mr. Gorenberg,
The US House of Representatives is deeply concerned by ongoing and pervasive acts of antisemitic
harassment and intimidation at the Massachusetts Institute of Technology (MIT). Failing to act decisively to ensure a safe learning environment for all students would be a grave dereliction of your responsibilities as President of MIT and Chair of the MIT Corporation.
This Congress will not stand idly by and allow an environment hostile to Jewish students to persist. The House believes that your institution is in violation of Title VI of the Civil Rights Act, and the inability or
unwillingness to rectify this violation through action requires accountability.
Postsecondary education is a unique opportunity for students to learn and have their ideas and beliefs challenged. However, universities receiving hundreds of millions of federal funds annually have denied
students that opportunity and have been hijacked to become venues for the promotion of terrorism, antisemitic harassment and intimidation, unlawful encampments, and in some cases, assaults and riots.
The House of Representatives will not countenance the use of federal funds to indoctrinate students into hateful, antisemitic, anti-American supporters of terrorism. Investigations into campus antisemitism by the Committee on Education and the Workforce and the Committee on Ways and Means have been expanded into a Congress-wide probe across all relevant jurisdictions to address this national crisis. The undersigned Committees will conduct oversight into the use of federal funds at MIT and its learning environment under authorities granted to each Committee.
• The Committee on Education and the Workforce has been investigating your institution since December 7, 2023. The Committee has broad jurisdiction over postsecondary education, including its compliance with Title VI of the Civil Rights Act, campus safety concerns over disruptions to the learning environment, and the awarding of federal student aid under the Higher Education Act.
• The Committee on Oversight and Accountability is investigating the sources of funding and other support flowing to groups espousing pro-Hamas propaganda and engaged in antisemitic harassment and intimidation of students. The Committee on Oversight and Accountability is the principal oversight committee of the US House of Representatives and has broad authority to investigate “any matter” at “any time” under House Rule X.
• The Committee on Ways and Means has been investigating several universities since November 15, 2023, when the Committee held a hearing entitled From Ivory Towers to Dark Corners: Investigating the Nexus Between Antisemitism, Tax-Exempt Universities, and Terror Financing. The Committee followed the hearing with letters to those institutions on January 10, 202
Read| The latest issue of The Challenger is here! We are thrilled to announce that our school paper has qualified for the NATIONAL SCHOOLS PRESS CONFERENCE (NSPC) 2024. Thank you for your unwavering support and trust. Dive into the stories that made us stand out!
How to Make a Field invisible in Odoo 17Celine George
It is possible to hide or invisible some fields in odoo. Commonly using “invisible” attribute in the field definition to invisible the fields. This slide will show how to make a field invisible in odoo 17.
1. JAVA ESSENTIAL TRAINING
Abstract Class
Interface
Linh LeVan
lelinh2302@gmail.com
http://tinhocbk123.appspot.com/
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VC
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Abstract Class
An abstract method is a method that is declared
without an implementation (without braces, and
followed by a semicolon), like this:
public abstract double getArea();
An abstract class is a class that is
declared abstract - it may or may not include
abstract methods.
Abstract classes cannot be instantiated, but they
can be sub-classed.
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BB
Abstract Class
If a class includes abstract methods,
the class itself must be declared abstract, as in:
public abstract class GraphicObject
{
//declare fields // declare non-abstract
methods abstract void draw();
}
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Extending an Abstract Class
public abstract class LivingThing {
public void breath() {
System.out.println("Living Thing breathing...");
}
public void eat() {
System.out.println("Living Thing eating...");
}
public abstract void walk();
}
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Extending an Abstract Class
When a concrete class extends the LivingThing
abstract class, it must implement the
abstract method walk(), or else, that subclass will
also become an abstract class, and therefore
cannot be instantiated. For example,
public class Human extends LivingThing {
public void walk() {
System.out.println("Human walks...");
}
}
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Exercises
Create an abstract class Figure having variables
dim1,dim2 of double type and an abstract method
area, then make two subclasses Rectangle and
Triangle which will implement the area method.
Create the abstract class reference variable,
assign subclass objects to it and print the
corresponding area.
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Multiple inheritance problem!
When we use the multiple inheritance, the child
class object can access all the methods of its
parent class.
Whenever we declare an object of child class
the system automatically loads all the methods
and variables of its superclass into that object.
But user generally does not work with all the
methods simultaneously.so why the object loads
all methods ,why not only required methods and
variables.
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BB
Interface solution
For this drawback multiple inheritance is not
included in java.so that we can declare only that
much thing we require.
Using interface, you can specify what a class
must do, but not how it does it.
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VC
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Defining an Interface
An interface is defined much like a class:
access interface name{
return-type method-name1(parameter-list);
return-type method-name2(parameter-list);
type final-varname1 = value;
type final-varname2 = value;
// ...
return-type method-nameN(parameter-list);
type final-varnameN = value;
}
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BB
Meaning…
Here, access is either public or not used.
When no access specified is included, then
default access results, and the interface is only
available to other members of the package in
which it is declared.
When it is declared as public, the interface can
be used by any other code.
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Meaning…
Name is the name of the interface, and can be
any valid identifier.
Notice that the methods which are declared
have no bodies. They end with a semicolon after
the parameter list.
They are, essentially, abstract methods; there
can be no default implementation of any method
specified within an interface.
Each class that includes an interface must
implement all of the methods. Variables can be
declared inside of interface declarations. 12
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Meaning…
Each class that includes an interface must
implement all of the methods.
Variables can be declared inside of interface
declarations. They are implicitly final and static,
meaning they cannot be changed by the
implementing class. They must also be initialized
with a constant value.
All methods and variables are implicitly public if
the interface, itself, is declared as public.
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BB
An example of an interface definition
public interface IGreeting {
public static final int MAX_MEMBER = 20;
public void sayHello();
}
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Implementing Interfaces
Once an interface has been defined, one or
more classes can implement that interface.
To implement an interface, include the
implements clause in a class definition, and then
create the methods defined by the interface.
access class classname [extends superclass]
[implements interface [,interface...]]{
// class-body
}
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Example
public class EnglishGreeting implements
IGreeting{
@Override
public void sayHello() {
System.out.println("Hello Guy!");
}
}
Note :When you implement an interface method, it must be declared as public.
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References to Interfaces
You can declare variables as object reference
that use an interface rather than a class type
When you call a method through one of these
references, the correct version will be called
based on the actual instance of the interface
being referred to. This one of the key features of
interface.
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References to Interfaces (cont’d)
Demo:
public class TestInterface {
public static void main(String[] args) {
IGreeting javaInterfaceExample =
new EnglishGreeting();
javaInterfaceExample.sayHello();
}
}
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Interface vs. Abstract Class
All methods of an Interface are abstract methods while
some methods of an Abstract class are abstract methods
Abstract methods of abstract class have abstract
modifier
An interface can only define constants while
abstract class can have fields
Interfaces have no direct inherited relationship with any
particular class, they are defined independently
Interfaces themselves have
inheritance relationship among themselves
If a class includes an interface but does not fully
implement the methods defined by that interface, then
that class must be declared as abstract. 19
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Interfaces Can Be Extended
One interface can inherit another by use of the
keyword extends. The syntax is the same as for
inheriting classes.
When a class implements an interface that
inherits another interface, it must provide
implementations for all methods defined within
the interface inheritance chain.
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Exercises
Define an interface having one method that takes
an integer parameter. For this method, provide two
implementations: In the first one,just print the value
and in the second one, print the square of
the number. Try to call both the versions.
21