• RELEVANCY SCORE 4.81

    DB:4.81:Main Difference Between Virtual And Abstract Method 19




    Hi All,
    Please explain themain difference between virtual and abstract.

    Thanks in advance.

    DB:4.81:Main Difference Between Virtual And Abstract Method 19

    1 more difference is...
    Abstract methods can reside in Abstract Class only. you cannot put abstract method inconcrete class.

  • RELEVANCY SCORE 3.72

    DB:3.72:Looking For Help On Abstract Method f1




    how to use an abstract method? what is the difference between abstract and inheritance?

    DB:3.72:Looking For Help On Abstract Method f1

    An abstract method is a method that has not been implemented -- only its name, arguments, and return type have been given. This is useful from a design-by-contract viewpoint.

    You use them by overriding them, providing an implementation. (Or by not overriding them, and letting your class be abstract as a result.)

    They're so different from inheritance that it's not really meaningful to discuss the differences. It's like asking what's the difference between abstract methods and a bowl of onion soup. But they're related in that if you subclass a class with an abstract method, then your subclass has inherited the type information (i.e., the contract, the requirement to provide something that implements that method).

  • RELEVANCY SCORE 3.51

    DB:3.51:Difference j9




    difference between abstract class and interface

    DB:3.51:Difference j9

    @OP You can see by the blatant obviousness and boring repetitiveness of these answers that this is a frequently asked question.

  • RELEVANCY SCORE 3.45

    DB:3.45:Abstract Classes And Interfaces? dp


    Can someone tell me whats the difference between abstract classes and interfaces?

    DB:3.45:Abstract Classes And Interfaces? dp

    ...alhough an abstract class doesn't have to have any abstract methods, or any methods at all for that matter. If it has an abstract method (or doesn't implement something from an interface it claims to implement) then it must be declared abstract, but the reverse is not true--any class may be declared abstract.

  • RELEVANCY SCORE 3.43

    DB:3.43:What Is The Difference Between Abstract Class And Interface jf


    Hi,
    Can you please tell me the differences between Abstract class and Interface.
    In which scenarios we have to use Abstract class and in which scenarios should use Interface.

    Thanks and Regards
    Kranthi

    DB:3.43:What Is The Difference Between Abstract Class And Interface jf

    http://stackoverflow.com/questions/761194/interface-vs-abstract-class-general-oo

  • RELEVANCY SCORE 3.37

    DB:3.37:Abstract Class Vs Interface ? 9d


    hi all,

    can anybody help me.

    if i have an abstract class (full of abstract method definitions) and an interface(having same definitions).

    Now the question is in which situation we go for an ABSTRACT CLASS with full of abstract method definitions and in which situation we go for an INTERFACE.

    and other differences between ABSTRACT CLASSES and INTERFACES except Multiple Inheritence ?

    DB:3.37:Abstract Class Vs Interface ? 9d

    Hi,
    All the variable inside the interface are static and final(You can't change it).While in case of abstract class it is not so. And in abstract class you can have concrete method also while in interface all the method must be non concrete So its depends on your requirement.

    Regards,
    Alok

  • RELEVANCY SCORE 3.24

    DB:3.24:What Is Difference Between Interface And Abstract? 3s


    Many time, I just confuse the purpose of interface and abstract.
    When should use interface or abstract in real world?
    Please give me the difference point alike point of both interface and abstract.

    Thank you.

    DB:3.24:What Is Difference Between Interface And Abstract? 3s

    Hi
    Take a look on this
    http://www.c-sharpcorner.com/UploadFile/yougerthen/104232008193919PM/1.aspx
    Reguards

    The complexity resides in the simplicity Follow me at: http://smartssolutions.blogspot.com

  • RELEVANCY SCORE 3.21

    DB:3.21:Interface And Abstract Class ac


    hi all,

    A method in an interface consists of access specifiers as public or abstract. what is the difference if the access specifiers for the method is public and abstract.

    regards,
    priya

    DB:3.21:Interface And Abstract Class ac

    That is correct. They must be because interface methods must be overridden when subclassed.

  • RELEVANCY SCORE 3.21

    DB:3.21:Difference Between Abstract Class And Interface j3


    What is the difference between anabstract class and aninterface ?

    DB:3.21:Difference Between Abstract Class And Interface j3

    Hi,
    Check this link differencebetween an abstract class and an interfacePS.Shakeer Hussain

  • RELEVANCY SCORE 3.20

    DB:3.20:Abstract Class Doubt ?? 7k


    what's the difference between the first abstract class and second abstract class .. when and where to use the first type and second type .. Please give me some info on it ...

    First Abstract Class
    public abstract class TestT where T : class
    {

    }

    Second Abstract Class

    public abstract class Test
    {

    }Regards, Gullu.

    DB:3.20:Abstract Class Doubt ?? 7k

    The second class is just a general abstract class - class that cannot be instantiated and is meant to provide common definition of a base class that multiple derived classes can share.
    More about abstract classes on MSDN.
    The first one is a generic abstract class that uses constraints to place requirements on the generic parameter (T). In your case the generic parameter can only be a type that match or inherit from specific base (you call this type 'class').
    e.g.

    public class Testable
    {

    public void Test()
    {
    //some logic here
    }

    }

    public abstract class TestT where T : Testable
    {
    public T t1;

    public void DoWork()
    {
    t1.Test(); //this will work because T must be of type Testable
    }
    }

    More about constraints on MSDN.

  • RELEVANCY SCORE 3.18

    DB:3.18:Difference Between Interface And Abstract Class 71


    I'm confused on what is the difference of implementing n abstract class and inheriting an interface?

    DB:3.18:Difference Between Interface And Abstract Class 71

    Hi,
    i want to add a few more differences --
    1.The variable defined inside an interface is public, static and final means it's basically a constant,But in case of abstract class you can hide the variable in the implementation class means you can change the value of the variable.

    One very important thing about the these two feature is when to use what?
    Ans:If a group of object is having some common property such that they are not going to be changed over a period then create an Abstract class out of that property.But if only some object is having a common property but not all then create an interface out of that property and implement all that property in Subclass.

    Thanks.

  • RELEVANCY SCORE 3.16

    DB:3.16:Difference Between Interface And Abstract Interface 8a


    What is the difference between the following?

    interface Sample{

    }and

    abstract interface Sample{

    }Please explain it with an example.

    DB:3.16:Difference Between Interface And Abstract Interface 8a

    An all the interface's methods are public and abstract, even if you don't declare them as such. And all it's variables are public, static final, even if you don't declare them as such.

  • RELEVANCY SCORE 3.13

    DB:3.13:Difference Between An Interface And An Abstract Class 9f


    Hey:

    I'm curious, what's the difference between an interface and an abstract class? Thanks.

    DB:3.13:Difference Between An Interface And An Abstract Class 9f

    "You have an abstract class if you want to implement some of the methods in it, but you do not want users to make instances of the class or do not want to implement all of the methods. Take a look at some of the abstract classes in java.util. Nearly all of the methods are implemented already so that it's far easier to create new data structures than if only interfaces were provided. "

    That's what I was looking for. Thanks.

  • RELEVANCY SCORE 3.11

    DB:3.11:Abstract Interface ss


    Hi All,
    What is abstract interface?What is the difference between Abstract interface and interface?
    If there is no difference why ServletRequest is abstract inteface.
    Thank You,
    Selvaraj

    DB:3.11:Abstract Interface ss

    Have a look at the JLS Chapter 9.1.1.1 abstract Interfaces
    Every interface is implicitly abstract. This modifier is obsolete and should not be used in new programs

  • RELEVANCY SCORE 3.09

    DB:3.09:Some Doubts In C++ af


    Hi All,     I have some doubts regarding C++ which i dint find from books or net1    Regarding Copy Constructor Assignment operator

    What is the actual use of Copy constructor(Other than Initializing with another object while constructing)
    why parameter of the copy constrctor  is (const ClassName Obj. ), i.e why we are recieving it as (reference). why not actual vaue i.e const ClassName Obj.
    what is the difference between Copy Constructor Assignment operator. When to use what???2    Regarding Virtual Function       What is the main use of virtual function other than overriding 3   why we cannot create the object of Abstract class      for ex:class A{public: void add(int a, inab);};we can create the object of class A even it has only declaration. Why not abstract class??4:   there is a linked list with many nodes. how can access last 3rd node with minimum iteration.If you know any one of the answer please reply this. No problemThese are the doubts which are not cleared for me. Thank you

    DB:3.09:Some Doubts In C++ af

     Hi, wrote:

    1    Regarding Copy Constructor Assignment operator

    What is the actual use of Copy constructor(Other than Initializing with another object while constructing)
    why parameter of the copy constrctor  is (const ClassName Obj. ), i.e why we are recieving it as (reference). why not actual vaue i.e const ClassName Obj.
    what is the difference between Copy Constructor Assignment operator. When to use what???

  • RELEVANCY SCORE 3.09

    DB:3.09:Difference Between Interface And Abstract Class a1


    Hi sirs,

    Give me the differences between interface and abstract class
    and when we go for interfaces and abstract class in developing an application

    DB:3.09:Difference Between Interface And Abstract Class a1

    An interface is a 100% abstract class, which means it doesn't contain any code, just method names and signatures. You use abstract classes when you want some code to be shared among the inheritors.

    The advantage with interface is that a class can implement as many interfaces as you like, while it can only extend one (abstract) class.

    So, you use interfaces when you need to extend other classes or doesn't want any code shared, and abstract classes when you don't want to extend other classes, and would like to share some code.

  • RELEVANCY SCORE 3.07

    DB:3.07:Difference Between Interface And Abstract Class mj


    hello friends give me the difference between interface and abstract class
    and link to find java material

    Thanx

  • RELEVANCY SCORE 3.06

    DB:3.06:Abstract Class Or Interface ? 11


    can any one tell me the difference between an abstract class an an interface. which is more useful ?

    DB:3.06:Abstract Class Or Interface ? 11

    You could also try searching this site for your question. It has been discussed in other threads as well (I posted a simialar (how do you spell that?) question).

  • RELEVANCY SCORE 3.06

    DB:3.06:Difference Between Abstract Class And Interface ca


    Hi everyone,

    CAn anyone explain why the following happen????

    --------------------------------------------------------------------------------
    Abstract class can have a constructor, Interface cannot.
    Abstract class can have static methods, Interface cannot.
    --------------------------------------------------------------------------------

  • RELEVANCY SCORE 3.05

    DB:3.05:Outbound And Abstract Sync Message Interface Difference zs



    Hi Experts,

    Is there any difference between the input and output messagetype for Outbound/Inbound Synch Message Interface and Abstract Sync Message Interface.

    Do we need to mention the same input and output messagetype for both outbound and Abstract or it should be otherway around?

    Regards

    Sara

    DB:3.05:Outbound And Abstract Sync Message Interface Difference zs


    ---Is there any difference between the input and output messagetype for Outbound/Inbound Synch Message Interface and Abstract Sync Message Interface.

    No there is not. U can select any message type irrespective of the type of message interface.

    ---Do we need to mention the same input and output messagetype for both outbound and Abstract or it should be otherway around?

    Yes. As per ur requirement u can specify the same.

    Regards,

    Prateek

  • RELEVANCY SCORE 3.05

    DB:3.05:Difference Between Main And Other Threads 31


    There are a lot many tings you cannot do n the main thread( the thread running the main Method) and other Threads how exactly do they differ?

    DB:3.05:Difference Between Main And Other Threads 31

    Why doesn't it allow running the static methods from
    main like dumpStack( )....You can run static methods from main. Do you mean the main thread or the main method?

    You can't call non-static methods directly from the main method, but that's just because it's static. You can't call non-static methods from any static method, without an instance on which to call them. Nothing special about main in that respect.

  • RELEVANCY SCORE 3.05

    DB:3.05:Difference Between Interface And Abstract Class? x1


    Hi,

    Can u plz explain
    at what scenarios we use interface and abstract class.?

    Thanks,
    B.Maruthi

    DB:3.05:Difference Between Interface And Abstract Class? x1

    If you had read the FAQ at the top of the forum home
    page you wouldn'y have bothered to ask this
    question.Anyways heres the link

    Read the question number 13 in this link

    http://access1.sun.com/FAQSets/newtojavatechfaq.htmlnice

  • RELEVANCY SCORE 3.05

    DB:3.05:Difference Between Abstract Interface And Normal Interface za


    Hello Friends,

    What is the Difference between abstract interface and normal interface?....

    DB:3.05:Difference Between Abstract Interface And Normal Interface za

    What is the Difference between abstract interface and
    normal interface?....The difference is that you didn't follow convention in the first case. All interfaces are implicitly abstract so you don't have to declare them as such.

  • RELEVANCY SCORE 3.05

    DB:3.05:What's The Difference Between Abstract Class And Interface? 1z


    Dear all,
    Can anyone give me some hints about this topic?

    Thanks.

    Leo

    DB:3.05:What's The Difference Between Abstract Class And Interface? 1z

    Also, you can only extend one class, but can implement many interfaces. I extend a class for true is-a relationships, I use implements like mixins.

  • RELEVANCY SCORE 3.05

    DB:3.05:Is Main A Abstract Method k8


    Is main a abstract method

    DB:3.05:Is Main A Abstract Method k8

    This main is not that main, but you can have an abstract main too.

    javap a
    Compiled from "a.java"

    public abstract class a extends java.lang.Object{
    public a();
    public abstract void main(java.lang.String[]);
    }

  • RELEVANCY SCORE 3.03

    DB:3.03:Interface &Amp; Abstract Class d3


    1whats the basic difference between an interface and an abstract class?
    when should one be using an interface or an abstract class?

    2whats the difference between method overriding and method overlaoding?
    does both of them has any relation with the instance of te class implementing them?

    DB:3.03:Interface &Amp; Abstract Class d3

    http://www.google.com/search?q=java+interface+%22abstract+class%22

    http://www.google.com/search?q=java+method+overloading+overriding

  • RELEVANCY SCORE 3.02

    DB:3.02:What Is The Difference Between Abstract Class And Interface af


    hi,recently i went for an interview they ask me what is abstract class ,interface and its difference
    I said abstract class contain abstact method ,abstract method is a method with no body.Abstract class cannot be instantiated.Abstract class is a base class it required derived class for the implementation of method.
    Interface is a syntactical contract that all derived class should follow
    it define properties ,method,events which are known as member of interface.
    Then They asked me what is the difference between them. I said
    abstract class interface
    1.abstact class can implement method 1.interface cant
    2.abstact class can contain constructor, 2.interface cant
    destructor
    3.abstract class cannot support multiple 3.interface support
    inheritance
    etc
    Then they said some different answer I said dont no.
    Then they ask me when i should make abstract class for an project and when
    i should make interface.
    I said if suppose there is two class which must be having method with different logic then we sholud make abstract class.
    and if suppose we have two class having method .with different logic then we can make interface .
    Am i correct with my explaination.if not correct me .please provide me that when should we create abstract class and interface and what is difference .please help me

    DB:3.02:What Is The Difference Between Abstract Class And Interface af

    I would focus the answer on the distinction that you cant add an abstract class to an existing class like you can an interface.

  • RELEVANCY SCORE 3.01

    DB:3.01:Abstract Classes Vs. Interfaces 3d


    An abstract method can only be implemented by a virtual method, while this is not necessarily so for a method declared in an interface.  Why must it be this way for abstract methods, and if so why is it not this way for methods declared in interfaces?
     
    Thanks!

    DB:3.01:Abstract Classes Vs. Interfaces 3d

    That was very informative, thank you.
     

  • RELEVANCY SCORE 2.99

    DB:2.99:Interface And Abstract Class Difference 18


    An interface can be used in such a way that we don't know the class of object assigned to a reference of that interface type until runtime. Can we use the abstract class in a similar way too?

    The difference between an abstract class and interface can be listed as
    1. Interface can not have implementation of any method
    2. The usage of interface and class is one other difference
    3. What other differences we have?

    DB:2.99:Interface And Abstract Class Difference 18

    941767 wrote:
    Here we have some more difference...Differences that mean nothing to an experience professional programmer.

  • RELEVANCY SCORE 2.99

    DB:2.99:Java Programming 33


    what is the difference between 'abstract' class and 'interface'

    DB:2.99:Java Programming 33

    Hey, get back in line. Don't jump the queue :)Well I guess I haven't qualified myself for this
    year's hunt. Maybe I could get a free-card because I
    was always on the Most Arrogant List a few years ago.Ok. I'll be nice. You'll get a free pass.

    Kaj

  • RELEVANCY SCORE 2.98

    DB:2.98:Re: Difference Between Abstract Class And Interface. f3


    Thanks, jverd. I have got it.

    George

  • RELEVANCY SCORE 2.98

    DB:2.98:Normal Class Vs Abstract Class kj


    Hi I have a question, When should we use abstract class,Normal methods with virtual methods also provide similar functionality, Only
    difference is we cannot instantiate abstract class.What are differences between normal class and abstract class.

    Regards,
    Shijith

    DB:2.98:Normal Class Vs Abstract Class kj

    Hello Shijith,
    Just for the title, I would recommend you read this thread:
    http://social.msdn.microsoft.com/Forums/vstudio/en-US/71e0e521-b742-48ee-a8a8-c7fdda8a2bc4/why-do-we-need-to-use-abstract-classes-interfaces-?forum=csharpgeneral
    Why abstract is used:
    An abstract class is a special kind of class that cannot be instantiated. So the question is why we need a
    class that cannot be instantiated? An abstract class is only to be sub-classed (inherited from). In other words, it only allows other
    classes to inherit from it but cannot be instantiated. The advantage is that it enforces certain hierarchies for all the subclasses.
    In simple words, it is a kind of contract that forces all the subclasses to carry on the same hierarchies or standards.
    Then please read this:
    http://stackoverflow.com/questions/391483/what-is-the-difference-between-an-abstract-function-and-a-virtual-function

    An abstract function can have no functionality. You're basically saying, any
    child class MUST give their own version of this method, however it's too general
    to even try to implement in the parent class. A virtual function, is basically
    saying look, here's the functionality that may or may not be good enough for the
    child class. So if it is good enough, use this method, if not, then override me,
    and provide your own functionality.

    I do think their explanation is good enough for your issue.
    Regards,
    Barry Wang
    We are trying to better understand customer views on social support experience, so your participation in this interview project would be greatly appreciated if you have time. Thanks for helping make community forums a great place.

    Click
    HERE to participate the survey.

  • RELEVANCY SCORE 2.98

    DB:2.98:What Is The Difference Between Abstract And Normal Class k1


    What will be the difference if I replaced :
    public abstract MyWork {
    ....
    }
    [/code]

    by public MyWork { ........
    }

    THanks in Advance

    Tleis

    DB:2.98:What Is The Difference Between Abstract And Normal Class k1

    To clear all that up for those guys:

    An abstract class must be subclassed or instantiated as an anonymous class. It can have any of the same members as a regular class and in addition it can define abstract methods. Any abstract methods must be implemented by the subclass or else that class too must be declared abstract.

    An abstract class is different from an interface. Java gives you only a single ancester in your class hierarchy. You will force an implementation to become a descendant of your abstract class -- and therefore no other. In "object oriented programming", the term "an 'is-a' relationship" is used to describe that relationship between any subclass and its superclass. However you like to put it: this is the relationship you will be defining when you write your abstract class.

    - Steev.

  • RELEVANCY SCORE 2.97

    DB:2.97:Diff Between Lsmw And Other pm



    what is the main difference between lsmw and sesion,calltransaction method?

    DB:2.97:Diff Between Lsmw And Other pm


    Hi,

    chk this.

    Session method.

    1) synchronous processing.

    2) can tranfer large amount of data.

    3) processing is slower.

    4) error log is created

    5) data is not updated until session is processed.

    Call transaction.

    1) asynchronous processing

    2) can transfer small amount of data

    3) processing is faster.

    4) errors need to be handled explicitly

    5) data is updated automatically

    Session method is to populate the data by filling BDC structure

    and keep as session to process from SM37 to post in appropriate Transaction.

    Call transaction method is to post the data directly into the Transaction from an Executable program.

    Regards,

    Anver

  • RELEVANCY SCORE 2.95

    DB:2.95:Bdc fj



    what is difference between bdc and lsmw?in which situation we prefer bdc and which situation we prefer lsmw?

    in lsmw what is the main reason we use mostly in batch input method for upload the data with comparing to other methods?what is the main reason?

    in bdc what is the main difference between batch input method and direct input method?

    what are the major disadvantage's in direct input method with comparing to batch input method?

    DB:2.95:Bdc fj


    hi,

    LSMW is generally for normal SAP applications, while BDC is mainly for any customized application.

    LSMW provides various methods for the migration of data, namely, those of direct input, Batch input recording and IDOC. BDC however, simply makes use of recording. There are two ways of implementing BDC, the call transaction method and the session method.

    In LSMW, mapping is taken care of with the help of SAP, whereas in BDC one has to provide explicit mapping directions.

    Coding is not very flexible in LSMW, whereas in BDC, coding is very flexible and applications can be easily customized. This is mainly because LSMW is devised specially for functional consultants who do not perform coding, while BDC is mainly made use of by technical consultants, who do perform coding.

    reward points if helpful.

    Thanks and Rewards.

  • RELEVANCY SCORE 2.94

    DB:2.94:What Is The Actual Difference Between Interfaces &Amp; Abstract Classes..? 73


    Hi Friends..!

    Please let me know what is the actual difference between Interfaces and Abstract Classes. All we can do in Abstract classes(ofcourse, except method definitions), is still possible to do in Interfaces. Then, why the concept of Abstract classes..?

    In which situation, we need Interfaces rather than Abstract classes and Vice-Versa..?

    Regards,
    k.suresh

  • RELEVANCY SCORE 2.92

    DB:2.92:Difference ???? xz


    What's the difference between an Interface and Abstract class ??????

    DB:2.92:Difference ???? xz

    Is google broken again?
    [http://www.google.co.uk/search?q=What's+the+difference+between+an+Interface+and+Abstract+class] 652,000 hits

  • RELEVANCY SCORE 2.92

    DB:2.92:Diff Between Interface And Abstract Class 9a



    Hi to all,

    I am woking on OOP in ABAP .Could any one can tell the difference between interface and abstract class.

    thanks in advance .

    DB:2.92:Diff Between Interface And Abstract Class 9a


    Hello Sagar,

    like Uwe told one basic difference is that you may provide some methods with an abstract class but not with an interface. The unique feature of interfaces is that you may implement several ones while abstract classes are limited to one inheritance hierarchy.

    Regards

    Klaus

  • RELEVANCY SCORE 2.91

    DB:2.91:Interfaces Vs Abstract Classes Why Even Use Contracts? x1


    Okay, I know there are lots of posts on this. I've read several and they have all helped me get to a reasonable understanding of the differences between both; however, I still can not seem to comprehend
    why anyone would need to enforce a contract for sub classes to follow?

    Correct me if I am wrong abstract classes and interfaces are both basically the same thing with the main difference being a subclass can inherit multiple interfaces while it would not be able to implement more than one abstract class.

    So then this is where I get confused. I know that abstract classes do allow implementation of methods declared virtual which can beoverridden in subclasses. This seems like a very useful technique and I can understand why one would use an abstract
    class for this purpose.

    Now I don't understand why someone would use an abstract class or interface with no type of implementation. Why not just cut those out and define your classes?

    //Not written in VS. Might have typos

    public interface ICanine
    {
    public void Bark();

    }

    public class Beagle : ICanine
    {
    public void Bark()
    {
    //Bark
    }
    }

    public class Wolf : ICanine
    {
    public void Bark()
    {
    //Bark
    }

    }

    //Why not omit the interface and just do this instead?

    public abstract class Canine
    {
    public virtual void Bark()
    {
    //Perform Function A
    }
    }

    public class Beagle
    {
    //Base class Bark Suffices
    }

    public class Wolf
    {
    public override void Bark()
    {
    //Perform function B
    }

    }

    //I just don't see the point in implementing something that has no functionality.

    DB:2.91:Interfaces Vs Abstract Classes Why Even Use Contracts? x1

    Hello,
    Please look into below links you will get your answer.
    1.
    Abstraction Class
    2.InterfaceClass
    3.
    Difference between Interface and Abstraction Class
    Hope it will help for you.
    thanks.

  • RELEVANCY SCORE 2.91

    DB:2.91:Abstract/Virtual Events a3


    If you have an abstract base class which has an event that children may
    implement, and none of the base class methods connect or raise the
    event, then what's the difference between declaring that event as
    either abstract or virtual?  I can't find much of anything in the
    docs about abstract or virtual events.  

    DB:2.91:Abstract/Virtual Events a3

    IIRC (and bear with me, since I'm not near any docs), an event is effectively a field of type delegate, along with three hidden methods: raise, add and remove. Fields cannot be virtual, so one would assume that the virtual refers to the methods associated with the field.
    The base implementation of add, simply adds the delegate to the InvocationList of the delegate field, the remove reverses this operation, and the raise invokes the delegate.
    When you say MyEvent(this, EventArgs.Empty) for example, you are effectively calling the raise method. Now the interesting thing is that AFAIK you cannot override the add, remove raise methods. I can't remember why, but I'm fairly confident I'm right on this one. This sorta makes the virtual superfluous.
    If you want child classes to fire the event, the pattern is to provide a protected virtual OnEventName method which fires the method. This allows the child class to stop the event being fired if neccessary, and also to invoke it itself:
    class Parent {

    public event EventHandler MyEvent;
    protected virtual OnMyEvent() {

    if(MyEvent != null) {

    MyEvent(this, EventArgs.Empty);
    }
    }
    }
    class Child : Parent {

    public void MyMethod() {

    // Some code
    OnMyEvent(); // Fire MyEvent
    }
    // Optional, if you want to do stuff even if the event handler is not hooked up, or
    // want to modify when MyEvent is fired:
    protected void override OnMyEvent() {

    base.OnMyEvent(); // Fire MyEvent, if you want to.
    // Do some stuff.

    }

  • RELEVANCY SCORE 2.90

    DB:2.90:In C# Is It Correct To Refer To An Abstract Method As A Pure Virtual Method? xd


    A C pure virtual method is not the same as a C# abstract method -but a colleague insists it is correct to call an abstract method a pure virtual method. Any references you can identify will be appreciated.
    Thanks!

    DB:2.90:In C# Is It Correct To Refer To An Abstract Method As A Pure Virtual Method? xd

    They are functionally the same.
    In C the abstract keyword is missing (which will be introduced afaics in the upcoming official C0x
    standard, and which along with override and sealed exists in VC since .NET 2.0/Visual Studio to make C/CLI CLR-compatible)
    but C had a concept of abstract classes and methods anyhow from day one,
    which C# seems to have inherited.

    A soon as a C class has at least one pure virtual function it is conceptionally abstract,
    i.e. cannot be intantiated and must be derived, although there is no keyword for that on the
    class level.

    In C# an abstract function is always virtual and a class with at least one abstract member
    is itself abstract, it cannot be instantiated and must be derived.
    It is the same pattern.

    In both C# and C abstract classes may also expose non-abstract members,
    that may or may not be virtual.
    So abstract classes can have partial implementation in both languages.
    A difference between C and C# is that an abstract C#-class does not need to expose
    any abstract members.

    A C class that only consists of pure virtual functions is btw conceptionally an interface
    where the interface keyword is also not part of the current C standard.
    All COM-interfaces are btw declared as such pure virtual classes.

    So these patterns are very similar in these two C-styled languages.
    Chris

  • RELEVANCY SCORE 2.90

    DB:2.90:J2ee Questions jj


    1. In EJB 2.0 , if Bean class has all settor and gettor method abstract
    then where it's implementation is done?

    2.What is the difference between Local and Remote Interfaces in EJB 2.0?

    3.How DSN less connection is done for EJB 2.0 ?

    DB:2.90:J2ee Questions jj

    I would confirm this answer from another PRO in J2EE,

    A Local interface will be used to fetch the skeleton code without doing a RMI call, meaning, when the EJB client is local the cleint can locate the EJB locally without making a RMI-IIOP call.

    IF you hvae more information regarding this, please update me, bthirnrayan@hotmail.com

  • RELEVANCY SCORE 2.90

    DB:2.90:Difference zk


    what is the depricate method?
    wahat is main difference between
    sendRediect()
    forward()
    include()

    DB:2.90:Difference zk

    what is the depricate method?http://java.sun.com/j2se/1.5.0/docs/guide/javadoc/deprecation/deprecation.html

    wahat is main difference between
    sendRediect()
    forward()
    include()Some of those are server side only and some send HTTP 300 series responses to clients. There's a lot of differences really, they aren't really comparable.

  • RELEVANCY SCORE 2.90

    DB:2.90:Difference 7x


    Hi sirs,
    Give me the main differences between abstract class and interface.Dont give me the links sir,

    when we go to use for the interface and for abstract class in developing an application

    DB:2.90:Difference 7x

    Another link:
    {color:#0000ff}http://forum.java.sun.com/thread.jspa?messageID=9961601{color}

    db

  • RELEVANCY SCORE 2.90

    DB:2.90:Swing And Awt ax


    What is the difference between Swing and the Abstract Window Toolkit?

    DB:2.90:Swing And Awt ax

    Ok thank you. Sorry you double posting :).

  • RELEVANCY SCORE 2.90

    DB:2.90:Difference Between Java Method And A Java Function 3d


    what is the difference between a method in java and a function
    in java ?

    ( i have seen that main() is called a function but the others
    are method )

    is it for main can only be called by JVM ?

    please help if u can...

    suman
    ( suman2k2@yahoo.com )

    DB:2.90:Difference Between Java Method And A Java Function 3d

    Pascal's version was:
    - function: returns a value (often a short bit of code)
    - procedure: does work, does not return a value (often longer bits of code)

    I also don't appreciate it when common terms are redefined, and I bet I'm not alone.

    When you dealing with those less picky with language and are discussing a function/method/procedure and use the word "function" they will know what you mean: a logical construct that seperates a section of code, may receive parametres and may return values. Saying "I have a function that does this" when you actually don't return a value will still get you understood in most non-academic settings.

  • RELEVANCY SCORE 2.90

    DB:2.90:Interface And Abstract Class c8


    Hi,

    Could you please let me know what is the exact difference between interface and abstract class.Which one is better to use .Could you please give me indepth answer.

    DB:2.90:Interface And Abstract Class c8

    Stop. Stop. Stop. I beg you...You're behaving like a Chinese gentleman with sand in his boots. Stop.

    Do we save the execution time by using interface.This is a compiler/byte code related question. Please post it in the proper place.

    What might be the behaviour inside the memory
    location by using interface and abstract class.Same answer.

    /Morten

  • RELEVANCY SCORE 2.90

    DB:2.90:Concept Of Abstract Class &Amp; Interface fc


    Hi friends,

    My question is what is the main difference between Abstract class Interface?

  • RELEVANCY SCORE 2.89

    DB:2.89:Readonlystringproperty Vs Stringexpression kd


    Where is the difference between them?

    From the JavaDoc it seems ReadOnlyStringProperty overrides equals, hashcode and toString. But I see no difference when using toString. Where is the reals benefit to each of them?

    Another thing: Why are there so many interfaces and abstract classes in javafx.beans.*? This is confusing.
    I mean:

    ReadOnlyProperty
    StringExpression
    ObservableObjectValuejava.lang.String
    ObservableStringValue
    ObservableValuejava.lang.String

    ===

    ObservableObjectValuejava.lang.String and ObservableStringValue are basically the same and only add one method (get()) to ObservableValue.

    Why so many interfaces?

    DB:2.89:Readonlystringproperty Vs Stringexpression kd

    Sorry for not being clear. It is always confusing which site is meant when talking about bindings.

    If you have a read only property p, you can bind another property to it (a.bind(p) works), but you cannot bind the read only property to something else (p.bind(a) does not work).

  • RELEVANCY SCORE 2.89

    DB:2.89:Subclass Vs Concrete Class fs


    Hi,

    What is the exact difference between subclass and concrete class?

    What is the need in subclassing abstract class to again abstract class?

    Thanks in Advance,
    venu.

    DB:2.89:Subclass Vs Concrete Class fs

    Hi,

    U mean to say Concrete classes are instantiatable
    and every concrete class is a subclass of some
    super class.Plz clarify me if i am wrong.That's correct. But it's also true that every class--both concrete and abstract--is a subclass of some superclass, except Object which has no superclass.

    NOTE: The following is simply provided in the interest of completeness because I'm a ballsniffing pedant. It's not that important to what you're asking about, and may just cause more confusion. Feel free to ignore it.

    Also, it's possible to make a concrete class non-instantiable by having a single private constructor and throwing an exception from it, but that's a runtime issue--the compiler will let you insstantiate the class (only from within itself if the c'tor is private).

  • RELEVANCY SCORE 2.89

    DB:2.89:Regarding Design Pattern pk


    What is the main difference between Singleton Pattern and static method. I can create a class with all static. Then why we can use singleton. Whats the main difference.

    DB:2.89:Regarding Design Pattern pk

    I think you got a couple of your explanations crossed, there...

    A Singleton is able to "maintain state" as soon as it's instantiated because it retains a reference to itself - it will not be garbage-collected until the ClassLoader that loaded it is disposed of. The pattern ensures a "one and only one" instance.

    A class with static members retains the state of those members across instantiations (still within the context of the ClassLoader), because those variables are stored in the Class object (which is instantiated when loaded). Thus, you can have multiple instances of a class that "share" that data. The problem with this, especially in a distributed environment, is that you then introduce some pretty interesting threading and synchronization issues.

    (This is not to imply that just by having a Singleton gets you out of those issues - they're just not in the same "place" in the JVM nor are they treated entirely the same.)

    Static methods should only be used for "utiity" functionality - just do one thing (like a calculation) and maintain no state.

  • RELEVANCY SCORE 2.89

    DB:2.89:Abstract Class 13


    Difference between abstract class and interface
    use of abstract class

    DB:2.89:Abstract Class 13

    This question has been asked here about a billion times:

    http://search.java.sun.com/search/java/index.jsp?qt=interfacenh=10qp=st=11rf=0since=country=language=charset=variant=col=javaforums

  • RELEVANCY SCORE 2.87

    DB:2.87:Difference Between Message And Method f9


    What is the difference between a message and method

    DB:2.87:Difference Between Message And Method f9

    When one is being careful and differentiating...

    For the code:

    bdlh.placeOrder(menu);The message is placeOrder(menu) and the method is the particular implementation of placeOrder that gets invoked.

  • RELEVANCY SCORE 2.87

    DB:2.87:What Is Difference Between Abstraction And Abstract Class ? j3


    What is difference between abstraction and abstract class ?

  • RELEVANCY SCORE 2.87

    DB:2.87:What Is The Main Diffrence Between Abstractclass And Interface? 87


    Hi Could anyone please explain me about main difference of abstractClass and Interface.And please give me one real Time scenario Ex:like I have requirement like Library module---Can I take the Library as an interface. I know the basic differences of interface and abstract class.

    DB:2.87:What Is The Main Diffrence Between Abstractclass And Interface? 87

    If there is a easier relation ship between the class then we can go for abstract class.Let take the example..Abstract Class:abstract class Mammals (It may be a HumanBeing or Animal){Eye(){Can set with two eyes;}abstract legs(); // we cant define the method. So it should be a abstract. Because human has two legs where as animals have four legs.}Interface:Completely different class has a same behaviours.Flyer (behavior)Bird Airplane SupermanHere three class have a same behaviour (flyer) but different implementation .

  • RELEVANCY SCORE 2.86

    DB:2.86:[C++/Cli] Suggestion For Abstract Method Notation c9


    When declaring an abstract method in C++/CLI, the following is equivalent:ref class Abstract abstract{
    virtual void abstract_method() abstract;

    DB:2.86:[C++/Cli] Suggestion For Abstract Method Notation c9

    Post this suggestion at http://connect.microsoft.com/VisualStudio.

  • RELEVANCY SCORE 2.86

    DB:2.86:Differance Between Abstract Class And Interface 7s


    Whats the main differance between abstract class and Interface and where I can use abstract class and where I can use Interface

    DB:2.86:Differance Between Abstract Class And Interface 7s

    Refer to
    http://www.javaworld.com/javaworld/jw-09-2001/jw-0921-interface.html

  • RELEVANCY SCORE 2.86

    DB:2.86:What Is The Exact Difference Between Abstract Classes And Interface 7m


    What is the exact difference between abstract classes and interface in real scenario???

    Plz could you give a practical example???

    Thanks

    DB:2.86:What Is The Exact Difference Between Abstract Classes And Interface 7m

    At least your head doesn't make a plonk sound.Mine just makes a splutchy bursting watermelon type sound.

    To the original poster - to make things simple, if there is any doubt about which you should use, use an interface. If the situation calls for an abstract class, you will know that an interface is the wrong choice, because it will be impossible to do what you want to do with an interface.

    Drake

  • RELEVANCY SCORE 2.86

    DB:2.86:Need Help With Abstract Method ? 7p


    **************************************************
    public abstract void sleep()
    {
    ..........
    }
    **************************************************
    Could someone please tell me what is the difference of an abstract method in comparing to an instance or a class method? How should I do the invocation to an abstract method by other methods of its own class and of another class? Must I define abstract methods within abstract classes? Do I need to redefine abstract methods before using them? Thanx!

  • RELEVANCY SCORE 2.86

    DB:2.86:Regarding Dynamic Binding And Abstract Class pp


    Hello Java Community,

    In dynamic biniding consept, it binds the appropriate method at run time... can any one please give me the reason how it identifes that perticular method is nearst one.....( i know that it first check sub class and then goes to super class ....... i just want how it identifys this process).....

    As per java soft new release JDK1.5 we can also write abstract class with out implimenting methods(even partially also) ... in this case if i declare all methods in abstract class were "public abstract " (like in interface methods return type) it will be similar as interface ......... and i just want in this case what is the difference between interface and abstrace class

    DB:2.86:Regarding Dynamic Binding And Abstract Class pp

    hello Sumit.Tyagi

    Thanks Q for responding...... and thanks for clearing my doubt....

    Regards
    sricharan

  • RELEVANCY SCORE 2.85

    DB:2.85:Regarding The Abstract And Interface km


    hai,
    I am new to java programming

    I want to difference between abstract interface,interface and abstract class

    public abstract interface Test{}

    public interface Test{}

    public abstract class Test{}

    which kind of situations use the above interfaces and abstract classes

    It would be helpfull if explain with example....

    Thanks

    DB:2.85:Regarding The Abstract And Interface km

    shashikumar, please don't multipost and don't use the browser's back button to edit your post. This creates multiple posts. I've removed the other thread you started a minute after this one.

    db

  • RELEVANCY SCORE 2.85

    DB:2.85:Difference Between Abstract Class And Interface ? fz


    CAN ANY BODY TELL ME THE DIFFERENCE BETWEEN THE ABSTRACT CLASS AND INTERFACE ?

    DB:2.85:Difference Between Abstract Class And Interface ? fz

    - An abstract class is a class that can not be instantiated but that can contain code, i.e. it gives you the ability to specify default implementations of methods.

    - An interface only contains methods but does not contain any code and you need to implement all the methods defined in the interface.
    - Interfaces may be multiple-inherited, abstract classes may not
    http://www.codeproject.com/Articles/11155/Abstract-Class-versus-Interface
    http://stackoverflow.com/questions/56867/interface-vs-base-class

  • RELEVANCY SCORE 2.85

    DB:2.85:Please Suggest 7p


    public abstract MyClass
    {
    public abstract void method1();
    public abstract void method2();
    }

    public interface MyInterface
    {
    public abstract void method1();
    public abstract void method2();
    }

    What is the difference between these two ?

    DB:2.85:Please Suggest 7p

    What exactly is your question? Are you trying to understand the difference between an abstract class and interface?

  • RELEVANCY SCORE 2.85

    DB:2.85:C++/Cli Versus C++ Inheritance d8


    Hi all, I have noticed a curious difference between how I would expect pure c++ and c++/cli to behave regarding inheritance of interfaces and I want to know if I have missed something obvious. I have an abstract base class which inherits from ICloneable, and some derived classes which I want to ensure actually implement the clone - ie I want the code to fail to compile if I have forgotten to implement ICloneable in one of my derived classes. The following is a distillation of the sort of structure I want:
    ref class AbstractBase abstract : public System::ICloneable
    {
    public:
    // virtual Object ^ Clone() { return nullptr; }
    };

    ref class Derived : public AbstractBase
    {
    public:
    virtual Object ^ Clone() /*override*/ { return gcnew Derived(); };
    };

    void Foo()
    {
    Derived ^ obj = gcnew Derived();
    Derived ^ newObj = safe_castDerived ^(obj-Clone());
    }

    This does not compile - the compiler expects the intermediate abstract level to implement ICloneable. If I introduce the commented out Clone function in AbstractBase (and the override in Derived), then this compiles, but I lose the enforcement at compile time that all the derived classes implement Clone(). I could put in another abstract method in the intermediate abstract class which forwards the call to the Clone method, but this seems a bit messy. As an experiment to see whether I was forgetting my c++ already ;) I tried to do something similar in c++ as follows:
    class CPP_ICloneable
    {
    public:
    virtual void * Clone() = 0;
    };

    class CPP_AbstractBase : public CPP_ICloneable
    {
    };

    class CPP_Derived : public CPP_AbstractBase
    {
    public:
    virtual void * Clone() { return new CPP_Derived(); }
    };

    void Foo()
    {
    CPP_Derived obj;
    CPP_Derived * newObj = reinterpret_castCPP_Derived *(obj.Clone());
    delete newObj;
    }

    This compiles fine and enforces that the derived class implements the Clone function - ie I get a compile time error if it is not present. So my question boils down to why is there a difference and is there a clean way of reproducing the c++ behaviour? Any thoughts?

    DB:2.85:C++/Cli Versus C++ Inheritance d8

    Thanks - yes, that's the obvious thing I was missing!!

  • RELEVANCY SCORE 2.84

    DB:2.84:What Is The Main Difference B/W Interface And Abstract Class 83


    is there any specific difference b/w interface and abstract class. if wht is tht? and how?

    DB:2.84:What Is The Main Difference B/W Interface And Abstract Class 83

    abstract class can be have methods with body

    interface cannot

    interface is 100% abstract class

  • RELEVANCY SCORE 2.83

    DB:2.83:Simple Query ac


    Difference between Abstract class and interface with practical example

    DB:2.83:Simple Query ac

    You are right; it was a simple query. (and I don't mean "simple" as in lacking complexity.)

  • RELEVANCY SCORE 2.83

    DB:2.83:Abstract Class And Interface???? 39


    hi all, i would like to know the difference between abstract class and interface....could anybody enlighten me on this....

    DB:2.83:Abstract Class And Interface???? 39

    P.S. don't be a loser an put up multiple posts, especially on something so easy to do a search on.

  • RELEVANCY SCORE 2.81

    DB:2.81:Difference Between Factory And Abstract Factory Pattern 1s


    Hi All

    What is the difference between Factory and Abstract Factory Pattern. I often get confuse between them

    Thanks in advance
    anu

  • RELEVANCY SCORE 2.81

    DB:2.81:Interfaces And Abstract Classes fk


    hi,

    Can anyone help me regarding the difference between interfaces and abstract classes. What is the advantage of interface over abstract classes and viceversa. Obout the possibities of multple inheritance I know. I found allmost all people are talking some external answers.
    Why an abstract class cant we do it with concrete class.
    regards,

    Jayaprasad Viswanathan

    DB:2.81:Interfaces And Abstract Classes fk

    Abstarct class can never be instantiated. Same as interfaces.

    Can be
    subclassed.Same as interfaces.

  • RELEVANCY SCORE 2.81

    DB:2.81:Abstract Class 71


    Hi,
    can u tell me the exact difference between abstract class and interface.under which situations we should use this.

    DB:2.81:Abstract Class 71

    AmitChalwade123456 wrote:
    Anumanick wrote:
    Hi,
    can u tell me the exact difference between abstract class and interface.under which situations we should use this.A class implementing an interface must implement all of the methods defined in the interfacepublic abstract class ImNotImplementingThat implements Runnable {

    // public void run() {} I was going to implement this, but I can't be bothered

    }while a class extending an abstract class need not implement any of the methods defined in the abstract class. public class WhyAreYouMoaningAboutRead extends java.io.InputStream {

    // I won't compile, because I'm not implementing the abstract void method 'read'

    }Additionally, a class extending an abstract class can implement an infinite number of it's own methods.Erm

    An abstract class can contain non-abstract methods which do not have to be overridden in the subclass.Indeed

  • RELEVANCY SCORE 2.81

    DB:2.81:Inter Face And Abstract Class c3


    hi
    can u please tell me the difference between interface and an abstract class? In which situations they will be usefull.
    thank u
    shyam

  • RELEVANCY SCORE 2.79

    DB:2.79:Difference Between Abstract Class And The Normal Class 7k


    Hi...........

    can anyone tell me use of abstract class instead of normal class

    The main doubt for me is...
    1.why we are defining the abstract method in a abstract class and then implementing that in to the normal class.instead of that we can straight way create and implement the method in normal class right...../

    DB:2.79:Difference Between Abstract Class And The Normal Class 7k

    Class vs. interface
    Some say you should define all classes in terms of interfaces, but I think recommendation seems a bit extreme. I use interfaces when I see that something in my design will change frequently.

    For example, the Strategy pattern lets you swap new algorithms and processes into your program without altering the objects that use them. A media player might know how to play CDs, MP3s, and wav files. Of course, you don't want to hardcode those playback algorithms into the player; that will make it difficult to add a new format like AVI. Furthermore, your code will be littered with useless case statements. And to add insult to injury, you will need to update those case statements each time you add a new algorithm. All in all, this is not a very object-oriented way to program.

    With the Strategy pattern, you can simply encapsulate the algorithm behind an object. If you do that, you can provide new media plug-ins at any time. Let's call the plug-in class MediaStrategy. That object would have one method: playStream(Stream s). So to add a new algorithm, we simply extend our algorithm class. Now, when the program encounters the new media type, it simply delegates the playing of the stream to our media strategy. Of course, you'll need some plumbing to properly instantiate the algorithm strategies you will need.

    This is an excellent place to use an interface. We've used the Strategy pattern, which clearly indicates a place in the design that will change. Thus, you should define the strategy as an interface. You should generally favor interfaces over inheritance when you want an object to have a certain type; in this case, MediaStrategy. Relying on inheritance for type identity is dangerous; it locks you into a particular inheritance hierarchy. Java doesn't allow multiple inheritance, so you can't extend something that gives you a useful implementation or more type identity.

    Interface vs. abstract class
    Choosing interfaces and abstract classes is not an either/or proposition. If you need to change your design, make it an interface. However, you may have abstract classes that provide some default behavior. Abstract classes are excellent candidates inside of application frameworks.

    Abstract classes let you define some behaviors; they force your subclasses to provide others. For example, if you have an application framework, an abstract class may provide default services such as event and message handling. Those services allow your application to plug in to your application framework. However, there is some application-specific functionality that only your application can perform. Such functionality might include startup and shutdown tasks, which are often application-dependent. So instead of trying to define that behavior itself, the abstract base class can declare abstract shutdown and startup methods. The base class knows that it needs those methods, but an abstract class lets your class admit that it doesn't know how to perform those actions; it only knows that it must initiate the actions. When it is time to start up, the abstract class can call the startup method. When the base class calls this method, Java calls the method defined by the child class.

  • RELEVANCY SCORE 2.79

    DB:2.79:Confusion Between Abstract And Interface a8


    Hi all,
    i'm new to java, can somebody help to explain on abstract and interface method. As i know that abstract or interface does not provide implementation in the superclass and interface class respectively. All the implementation are done in subclass.. why not we use the inheritances and abstract method to solve the problem instead of using the interface... i can't see the difference between the abstract and interface.. can somebody provide me a good example to understand the interface well..

    p/s: pls correct me if i wrong... ;)
    thanks

    DB:2.79:Confusion Between Abstract And Interface a8


    public class abstract Mainclass{
    abstract double area();
    abstract double meter();
    }

    public class Subclass1 extends Mainclass{
    double area(){
    return 5+1;
    }
    }

    public class Subclass2 extends Mainclass{
    double area(){
    return 8+10;
    }
    }Let's say you have
    public class abstract AreaClass {
    abstract double area();
    abstract double meter();
    }And then when you are working on your second iteration and you want to use Dimension class for this purpose for your new code but you want to leave the old code alone. If you have made AreaClass an abstract class, this is impossible.
    public class AreaDimension extends AreaClass, Dimension {
    }will not compile. However if you had defined AreaClass as and interface you can do this:
    public class AreaDimension extends Dimension implements AreaClass {
    double area() {
    return height * width;
    }
    }Then you can pass this to any method that accepts an AreaClass as a parameter and you can also pass it to any method that takes a Dimension.

  • RELEVANCY SCORE 2.79

    DB:2.79:What Is The Difference Between Abstract And Interface? d8



    and pls tell me how to know tat

    wen to use static and instance

    DB:2.79:What Is The Difference Between Abstract And Interface? d8


    Abstract class can have single inheritance and Interface can have multiple inheritance.

    Class can have abstract method, which implementation not done itself and subclasses can do. it means class can partial abstract but not in case of interface.

    Kind Rgds

    Ravi Lanjewar

  • RELEVANCY SCORE 2.79

    DB:2.79:Why We Use Interface? c9


    I appeared one of my interviews.The Interviewee asked me a question that

    Suppose one is abstract class and one is interface.
    All the methods of abstract class are abstract.
    Then on this level what is the difference between abstract
    and interface and why we use interface. I could not answer properly.
    Please guide me the actual difference between Abstract class and Interface.
    Thanks

    DB:2.79:Why We Use Interface? c9

    google is your friend! Dear You are also my friend ;)

  • RELEVANCY SCORE 2.78

    DB:2.78:Difference Between A Abstract Class With 4 Abstract Methods And A Interface With 4 Abstract Methods. 8c


    what is the difference between Difference between a Abstract class with 4 abstract methods and a Interface with 4 abstract methods.

    DB:2.78:Difference Between A Abstract Class With 4 Abstract Methods And A Interface With 4 Abstract Methods. 8c

    Your question is better rephrased as: What is the difference between an abstract class and a interfase?
    This has been discused here
    http://social.msdn.microsoft.com/Forums/en-US/csharpgeneral/thread/67451957-f0bd-4b9b-a2c0-16f604ce8643
    Regards

  • RELEVANCY SCORE 2.78

    DB:2.78:Difference Between Compare Nad Compareto Method k8


    difference between compare nad compareTo method

    DB:2.78:Difference Between Compare Nad Compareto Method k8

    It's best not to reward people who don't express their questions properly. Otherwise we'll only get more of the same.

  • RELEVANCY SCORE 2.77

    DB:2.77:Difference Between Inteerface And Abstract 11


    Hi,Please Anyone can tell me What is the difference between Abstract and Interface?Where we can use interface and where we can use abstract?What is the uses of both?

    DB:2.77:Difference Between Inteerface And Abstract 11

    I agree with the all of the above, just adding one more thing:
    An interface is a pure abstract

  • RELEVANCY SCORE 2.77

    DB:2.77:Re: Difference Between Abstract Class And Interface 7k


    See reply #44 and then please find something more useful to do.

    DB:2.77:Re: Difference Between Abstract Class And Interface 7k

    Passionate_Java_Lover_Vijay wrote:
    hi tigers,
    i am very new to java.
    i have a doublt iin collection.
    at wht situation what interface wil be best than other.

    where should i use List Set, Map and all.
    Advance thanks 2 guys who help me.

    Thanks
    ThinkGodJebus. Are you for real? Get a grip will you

  • RELEVANCY SCORE 2.77

    DB:2.77:Re: Difference Between Abstract Class Ans Interface 39


    Abstract classes have atleast one method abstract and interfaces have all abstract methods.

    If you are developing some application in which any entity can have more than one implementation, it is good practice to use an interface and implement the classes using interfaces.

    If some of the functionality of an entity is already known and other methods can have different implementations, then creating an abstract class is better.

    It's all a part of having a good design. Look around in the API docs and you'd find lots of abstract classes and interfaces. Try to figure out why they are so... I hope I didn't confuse you.

    Read the URL for better View

    http://java.sys-con.com/read/36250.htm

  • RELEVANCY SCORE 2.76

    DB:2.76:Problem With Std::Thread 81


    Hi!
    Could someone answer my question, please?
    I have a class that has its own thread.
    struct CThread1 abstract : boost::noncopyable
    {
    CThread1() throw() {};
    CThread1( CThread1 Source ) throw();
    CThread1 operator = ( CThread1 Source ) throw();
    virtual ~CThread1() throw();
    void RunThread();
    virtual void Routine() throw() = 0;
    private:
    std::thread mThread;
    };
    It has a destructor:
    CThread1::~CThread1()
    {
    if( mThread.joinable() )
    mThread.join();
    }
    The problem is, that this class never exits join() method,
    but the thread's routine is finished.
    It looks like this bug:
    connect.microsoft.com
    The difference is, that my instance is a local variable (on the stack stack)

    In main function it should be closed correctly.
    P. S.
    Maybe this is a bug, but how to create the code without the problem?
    Would it be solved, may I wait for a better runtime,
    or is it my error?
    Thank you very much

    Włodzimierz O. Kubera

    DB:2.76:Problem With Std::Thread 81

    I must verify the problem another time.
    It looks like, that something has changed
    and this is not the bug found on the connect site.Włodzimierz O. Kubera

  • RELEVANCY SCORE 2.76

    DB:2.76:Wsdl's sp


    Hi All,

    What is difference between abstract and concret WSDLS in SOA??

    Can anybody help to understand this?

    - Thanks

    DB:2.76:Wsdl's sp

    refer below links,

    _http://oraclesoaonline.blogspot.co.uk/2011/12/difference-between-concreate-wsdl-and.html
    _http://pushplsingh.blogspot.co.uk/2011/12/difference-between-concrete-and.html

  • RELEVANCY SCORE 2.75

    DB:2.75:Virtual Methods- Abstract Methods 3k


    Hi, I need to get this clear in my head.
    In C++ you had virtual methods()
    If a method was virtual this made the enclosing class abstract.

    There is no such thing as abstract methods in C++?

    In java, if you have an abstract method your enclosing class becomes abstract.

    There is no such thing as a virtual method in java.

    is all the above correct?
    Thanks ... J

    DB:2.75:Virtual Methods- Abstract Methods 3k

    Hi, I need to get this clear in my head.In C++ you had virtual methods()
    If a method was virtual this made the enclosing class abstract.

    There is no such thing as abstract methods in C++?Incorrect.

    Abstract methods have no implementation. You can have those in C++. If I remember correctly, they'd look something like this:

    public void foo() = 0;In java, if you have an abstract method your
    enclosing class becomes abstract.There is no such thing as a virtual method in java.Incorrect.

    All methods in Java are virtual by default. Every method is fair game to be overridden by a subclass. You mark them with the final keyword to prohibit overriding.

    All methods in C++ are final by default. You can't override any method in a subclass unless you mark it with the virtual keyword. (This was keeping the Bjarne's philosophy of "only pay for what you use".)

    %

  • RELEVANCY SCORE 2.75

    DB:2.75:Abstract? Interface? dm


    Hello! Can anybody explain me the difference between abstract classes and interface? when should i use them? Can you please give me examples?

    Thank you in advance!

    DB:2.75:Abstract? Interface? dm

    *** Abstract:

    Abstract classes are classes which are not designed to be used by the programmer. They simply enforce the declaration of certain methods on any class which subclasses them. Abstract classes can contain method declarations and instance variables.

    An example would be a very simple driving game, which offers a choice of different cars. Each car moves in the same manner, acceleration, etc. The only difference is the graphic which is used to display each car on screen. For this implementation, it would make sense to have an abstract class 'Car' which defines all the methods such as getSpeed, getDirection, setSpeed, setDirection, and so on. Its one abstract method would be getGraphic. The Car class cannot define this method since it models the 'general case' car, and so does not know what graphic is appropriate for each car.

    abstract class Car {

    /**
    * Define all the methods which are appropriate for each Car object
    */
    public int getSpeed() {
    return speed;
    }

    public void setSpeed(int i) {
    speed=i;
    }

    //etc

    //declare the abstract method
    public abstract Icon getGraphic();
    }Now you could subclass the Car class for a particular Car object:
    public class Mini extends Car {
    public Icon getGraphic() {
    return new ImageIcon("Mini.gif");
    }
    }To summarise, abstract classes are useful if you have a set of similar objects which have most of the same properties, but some method(s) are only appropriate for each individual object.

    *** Interface:

    Interfaces are useful when you need to disguise your object(s) as another type of object. By implementing the interface, the VM can recognise this.

    Interfaces differ from abstract classes in that you must write all the functions yourself. They provide no properties or methods in the base class, whereas abstract classes do.

    I hope this helps, but you would probably be best to scour the java tutorial for this topic for better examples.

  • RELEVANCY SCORE 2.75

    DB:2.75:Help Pls! 87


    Hi, can someone pls tell me what the difference between a normal class and an 'abstract class' is.

    Thanx!

    DB:2.75:Help Pls! 87

    Chris Evans just rang to call it off, apparentley he'd rather be seen with someone cool like Danny Baker and that my wife was too old for him.
    So I'll knock up a quick batch of proper nosh and meet yer all there. Hope you all like Pie and Mash Suchi, beautiful.

    Jamie

  • RELEVANCY SCORE 2.74

    DB:2.74:Whats The Difference Between Abstract Classes And Interfaces? sp


    What's de advantage ov Interfaces and vice versa the advantage of the Abstract Classes?
    Thanks

    DB:2.74:Whats The Difference Between Abstract Classes And Interfaces? sp

    1. Interface only contains Skeleton methods (no implementation at all). An interface does not have member variables.

    2. Interface does not have access modifiers.
    3. However interfaces help us in achieving multiple inheritances i.e. a class cannot inherit multiple classes (also abstract class) but it can inherit multiple interfaces.

    4. Abstract class contains Skeleton methods as well as default implementation (common functionality).

    5. Abstract class contains member variables and access modifier (default is private).

    6. Use abstract class if you need to modify base class because once base class is modified, we don’t need to change sub classes. But in case of interface, once interface is created and used, we cannot change base class. In this case we may need to add new
    interface to accommodate required change.
    7. Use abstract class if you have to implement common functionality for closely related objects (default method with provide this).

    8. Use interface if you have to implement common functionality for uncommon objects or disparate objects (in sub class implementation will provide this).

  • RELEVANCY SCORE 2.74

    DB:2.74:Interface And Abstract Class dd


    what is the difference between interface and Abstract class?
    What are the situations we have to go for interface and Abstract class?

    DB:2.74:Interface And Abstract Class dd

    Neither an abstract class nor an interface can be instantiated (meaning you cannot create the object directly with the "new" keyword). They are both similar in that they have abstract methods. (Technically, you can create an abstract class with no abstract methods, but I would question the utility of making that class abstract in the first place).

    The two main differences are the following:

    Implementation: An abstract class can implement methods, since it is a class. An interface can never implement any methods, it only declares their signatures.Inheritance: A given class can implement an unlimited number of interfaces. A class can only extend one class. In general, I use the following rules of thumb when deciding (other developers may have differing opinions):

    Given the choice, use an interface. Since you can implement an unlimited number of interfaces, they are not as restricted, from a class hierarchy perspective. If you have several classes with the same instance (class) variables declared and several methods that all accomlplish the same thing (normally, they will even have segments of code copy-pasted between classes), then re-factor the common variables and code into an abstract class. When using interfaces, always consider delegation. Delegation is something like the following:interface IFoo {
    abstract public void bar();
    }

    public class FooDelegate {
    final public void bar() {
    // Default implementation goes here
    }
    }

    public class FooImpl implements IFoo {

    final public void bar() {
    new FooDelegate().bar();
    }
    }

    The advantage of delegation is that you can write a "helper" that contains the implementation, and then the classes that actually implement the interface can simply use the helper (e.g., delegate the implementation to another class).

    - Saish

    "My karma ran over your dogma." - Anon

  • RELEVANCY SCORE 2.74

    DB:2.74:Virtual And Abstract Properties 87


    Is it possible to make set method abstract and get method virtual for the same property?
    Thanks in advance.

    Regards,
    Kannan

    DB:2.74:Virtual And Abstract Properties 87

    Better make themethods getO, setO protected, not public. Only derivig classes should acces them; other callers should access the properties.
    Regards
    Christof

  • RELEVANCY SCORE 2.74

    DB:2.74:Abstract Class And Interface???? ja


    hi all, i would like to know the difference between abstract class and interface....could anybody enlighten me on this....

    DB:2.74:Abstract Class And Interface???? ja

    search the forums, lot's of times answered this one has been.

  • RELEVANCY SCORE 2.74

    DB:2.74:Difference B/W Abstract Class And Interface mf


    Hi,
    can anyone tell the difference between Abstract class and an Interface?

    Thanks in advance!

    DB:2.74:Difference B/W Abstract Class And Interface mf

    The majoor diiffernce is that Interface canot ber
    inherited while absract calss can be inherited
    one abract class can iheret other abstract class
    while Interface doesnot???

  • RELEVANCY SCORE 2.74

    DB:2.74:What's The Difference Between Equals() And Compareto() Method fd


    I'm confused between the two method from String class ,,, what's the main difference between equals() and compareTo() method?

    DB:2.74:What's The Difference Between Equals() And Compareto() Method fd

    Note also that many Collections objects rely on your class having an equals() method defined to tell if two objects in a collection are "equal". A compareTo() method will not do in this context.

    PC#178;

  • RELEVANCY SCORE 2.73

    DB:2.73:Java Interfaces 1a


    Java allows to put 'abstract' keyword while declaring an interface, but by definition interfaces are support to be abstract, so whether there is any specific meaning of declaring an interface abstract. I mean whats the difference between an interface and an abstract interface?

    DB:2.73:Java Interfaces 1a

    No difference whatsoever. I believe the "abstarct" keyword in interfaces is an ingheritance from previous versions

  • RELEVANCY SCORE 2.72

    DB:2.72:Abstract Classes And Interfaces kp


    I am kinda new to Java but have been studying frequently. I have a question that is probably very simple: What is the difference/advantage between an abstract Class and an Interface?

    DB:2.72:Abstract Classes And Interfaces kp

    Search the forum. Here's a topic that addresses it:
    http://forum.java.sun.com/thread.jsp?forum=31thread=273324

  • RELEVANCY SCORE 2.72

    DB:2.72:Re: What Is The Difference Between An Interface And An Abstract Class? 1a


    8000 views already wow.

    DB:2.72:Re: What Is The Difference Between An Interface And An Abstract Class? 1a

    filestream wrote:
    As the two famous politicians, Jonathan Curry and Larry Craig are wont to say, "Glad I could serve you."

    Of course, each says it in entirely different situations but we're not here to discuss that. The members of the forums are happy just knowing that we've cleared 1 doubt.Now that you mention it, I take a wide stance in the interface/abstract class issue.

  • RELEVANCY SCORE 2.72

    DB:2.72:What Is The Difference Between Abstract And Concrete Wsdl? ap


    What is the difference between Abstract and concrete WSDL?

    DB:2.72:What Is The Difference Between Abstract And Concrete Wsdl? ap

    see : https://blogs.oracle.com/aia/entry/aia_11g_best_practices_for_dec
    for an example

    we use the abstract wsdl's so we're able to develop the process wether or not the environment (of the concrete endpoint) is up and running

  • RELEVANCY SCORE 2.71

    DB:2.71:Abstract And Interface fa


    Dear Sir/Madam,

    Please let me know the difference between Abstract class and Interface.

    DB:2.71:Abstract And Interface fa

    I disappeared as i was checking the forums in javaworld.com, but now i will keep this site as main.

  • RELEVANCY SCORE 2.71

    DB:2.71:Difference Between Interface And Abstract Class zm


    What is the differrence between an abstract class and an interace? and when would you use one over the other?

    DB:2.71:Difference Between Interface And Abstract Class zm

    What is the differrence between an abstract class and
    an interace? and when would you use one over the
    other?To (over-)summarise:
    An interface defines what you want to do, but doesn't tell you how to do any of it.
    An abstract class may define some of how to do it, but not necessarily all.

    RObin

  • RELEVANCY SCORE 2.71

    DB:2.71:The Difference Between Factory Method Design Pattern And Abstract Factory fm


    Hi,
    They are verysimilarfrom UML. I want to know the differences between them and how to use them inactual world.
    I foundthere is only one instance in Factory method, but more than one in abstract Factory? please give me some samples to clarfiy me, thanks. I don't like links.

    DB:2.71:The Difference Between Factory Method Design Pattern And Abstract Factory fm

    Thanks very much, I think I got it now. thanks for your kindly reply.I am fish.

  • RELEVANCY SCORE 2.71

    DB:2.71:I Dont See Any Difference Between Abstract Method And Abstract Factory -Have You Find Any Difference ( Both Of Them Decouples The Client From Object Creation) 87


    I dont see any difference between Abstract method and Abstract factory - both of them decouples the client from object creation.
    If anybody knows the actual difference please explain me with differences
    Also i dont understand families of related or dependent object ..why we need to create families of related objects instead we can simply go for factory method rite ?

    Abstract method:- http://www.c-sharpcorner.com/uploadfile/kalisk/factory-method-design-pattern-using-C-Sharp/
    Abstract factory :http://lasithsameera.blogspot.com/2010/07/abstract-factory-pattern-with-c-code.html

    look at the above code...both samples are looks similar except in the Abstract factory delegates the object creation to another class..thats the only difference i can see.....Any thoughts?

    ilikemicrosoft

    DB:2.71:I Dont See Any Difference Between Abstract Method And Abstract Factory -Have You Find Any Difference ( Both Of Them Decouples The Client From Object Creation) 87

    I dont see any difference between Abstract method and Abstract factory - both of them decouples the client from object creation.
    If anybody knows the actual difference please explain me with differences
    Also i dont understand families of related or dependent object ..why we need to create families of related objects instead we can simply go for factory method rite ?

    Abstract method:- http://www.c-sharpcorner.com/uploadfile/kalisk/factory-method-design-pattern-using-C-Sharp/
    Abstract factory :http://lasithsameera.blogspot.com/2010/07/abstract-factory-pattern-with-c-code.html

    look at the above code...both samples are looks similar except in the Abstract factory delegates the object creation to another class..thats the only difference i can see.....Any thoughts?

    ilikemicrosoft

  • RELEVANCY SCORE 2.71

    DB:2.71:Difference Between Main Method In C++ And Java df


    What is the Difference between the Usage
    Of Main method Outside Class in C++ and
    Usage Of Main method inside the Class
    in java.

    i,e ..
    Main Method is Encapsulated inside the
    Class in Java
    But in c++ ,
    It is Outside the Class.

    Plz Give Explanations

    DB:2.71:Difference Between Main Method In C++ And Java df

    In C main is a global function because there aren't any other.
    In C++ main is a global function because of compatibility with C.
    In Java main is a class static function because there aren't any globals and because of the runtime environment where every class can be considered 'executable' if it has a main method with correct signature.

  • RELEVANCY SCORE 2.71

    DB:2.71:Abstract Inteface 87


    What is the difference between Abstract interface and interface ?
    if there is no difference,why ServletRequest ,etc are abstract interface.
    Thanks
    Selva

    DB:2.71:Abstract Inteface 87

    SelvaBalaji wrote:
    in the eclipse have opened the interface.and where did eclipse get it from? Remember that it doesn't really matter at all and so we should probably spend our time learning more useful stuff.

  • RELEVANCY SCORE 2.71

    DB:2.71:Can An Abstract Method Be Overridden By A Virtual Method 99


    Hi All,
             can an abstract method be overridden by a virtual method ?
             Can anyone explain me with an example.
    -Mahe
     

    DB:2.71:Can An Abstract Method Be Overridden By A Virtual Method 99

     
    Hi Peter,
                 Thanks for your Explanation.
    -Mahe1