• RELEVANCY SCORE 4.93

    DB:4.93:Diff. Between Interface And Abstract Class 8j




    hi,
    Can any one tell me about diff between interface and abstract class in practical way.advanced thanks for ur response.
    -PVMVS

    DB:4.93:Diff. Between Interface And Abstract Class 8j

    An interface is a way to specify a set of abstract methods that you want a class to implement. The big deal is that the compiler will check that the methods are in fact provided by the class.

    Interfaces almost always represent a view that has nothing to do with the class hierarchy. It could for example be a specific way to access data, like an iterator. Iterators have seldom anything to do with the logical class design. It's just a common way to iterate through the elements of any class.

  • RELEVANCY SCORE 4.93

    DB:4.93:Diff. Between Interface And Abstract Class 3s




    hi,
    Can any one tell me about diff between interface and abstract class in practical way.advanced thanks for ur response.
    -PVMVS

    DB:4.93:Diff. Between Interface And Abstract Class 3s

    This question gets asked all the time. I found lots of hits by searching this forum with the words: interface abstract class difference

    I'm sure google will return even more. Searching existing posts should always be done before posting.

  • RELEVANCY SCORE 4.77

    DB:4.77:Java Interfaces And Abstract Classed fc




    what is the difference between interface and abstract class?

    DB:4.77:Java Interfaces And Abstract Classed fc

    I suggest you try writing some code and see.

  • RELEVANCY SCORE 4.66

    DB:4.66: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:4.66:Differance Between Abstract Class And Interface 7s

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

  • RELEVANCY SCORE 4.63

    DB:4.63:Difference Between Abstract Classes Vs Interface 77


    Hi,
    Can u pls mention all the differences between Abstract Classes and Interface.? I've mentioned the differences I've known here.

    Known Differences:
    ------------------
    (*) An interface cannot implement any methods, whereas an abstract class can.
    (*) A class can implement many interfaces but can have only one superclass

    Can U pls mention at what situation(practical situation) we've to go for abstract class or Interface?
    Tell me the situation when we have to go for abstract class?
    Tell me the situation when we have to go for interface?

    Please Reply me
    Thanks Regards
    Venkatesh

  • RELEVANCY SCORE 4.47

    DB:4.47:Interface Or Abstract Class 1k


    Hi all, I am not sure when should I go for an interface and when should I go for an abstract class(both are abstractions ultimately)? Can anyone please give instance(s) where I should use an interface and not an abstract class and vice versa? Regards, Sandip

    DB:4.47:Interface Or Abstract Class 1k

    Hi TimJim,Thanks for your insight. I think even the following link is also quite good -http://social.msdn.microsoft.com/Forums/en-US/vblanguage/thread/511cce83-3b58-495d-8198-1df8bdc49fd0/Regards,Sandip

  • RELEVANCY SCORE 4.32

    DB:4.32:Interface Vs Abstract Class ?? z1


    Are there any guidlines when to use Interface and when abstract class.
    Tried to dig in book but failed. Will appreciated any links.

    Thanks
    Mario

  • RELEVANCY SCORE 4.31

    DB:4.31:Difference j9


    difference between abstract class and interface

    DB:4.31: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 4.22

    DB:4.22: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:4.22: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 4.11

    DB:4.11: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:4.11: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 4.09

    DB:4.09:When Would You Use An Abstract Class Versus Interface ? zc


    Hi guys

    When would you guys use an Abstract Class versus and Interface ?

    Stev

    DB:4.09:When Would You Use An Abstract Class Versus Interface ? zc

    Another important distinction: declaring functions abstract in a base class not only forces the programmer to implement the function, but also allows messages to be routed to the implemented version.

    Given the shape example from before, the getArea call only works because abstract tells the compiler "hey look for a function prototype that matches this in the derived class"

  • RELEVANCY SCORE 3.99

    DB:3.99:Why We Use Interface And Abstract Class mm


    hi,
    please explain me why and whenweneed to use interface and abstract class with real life example

    thanks in advance

    DB:3.99:Why We Use Interface And Abstract Class mm

    Hi Nitin,
    Here is major usage why we use Interface and abstract class, Interface need to be implement in small units but abstraction class needs to implement in large units. More clarifications is under below:
    1. Definition of
    Interface Class with sample.
    2.Definition ofabstraction class with sample.
    3.
    Difference betweenabstraction Interface class.
    Hope it will help you.
    thanks,

  • RELEVANCY SCORE 3.98

    DB:3.98: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:3.98: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 3.86

    DB:3.86: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:3.86:Abstract Class And Interface???? ja

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

  • RELEVANCY SCORE 3.84

    DB:3.84: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:3.84: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 3.84

    DB:3.84:Difference B/W Abstract &Amp; Interface dx


    Anyone tell me 4 difference b/w abstract class and interface
    plz help me

    DB:3.84:Difference B/W Abstract &Amp; Interface dx

    Asking once is enough.
    http://forum.java.sun.com/thread.jspa?threadID=734361

  • RELEVANCY SCORE 3.84

    DB:3.84:Difference B/W Abstract Class And Interface mf


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

    Thanks in advance!

    DB:3.84: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 3.82

    DB:3.82:Abstract Class Needs To Implement Interface ms


    Hello, I have an interface and base abstract class defined as follows: interface IbusinessInterface{    void DoSth1();    void DoSth2();    void DoSth3();    void DoSth4();    void DoSth5();    ...    ...    void DoSthN();}public abstract class BaseClass : IBusinessInterface{    public abstract void DoSth1();    public abstract void DoSth2();    public abstract void DoSth3();    public abstract void DoSth4();    public abstract void DoSth5();    ...    ...    public abstract void DoSthN();} what is the reason that this abstract class needs to have methods of the interface implemented  ?Thanks, Michal

    DB:3.82:Abstract Class Needs To Implement Interface ms

    Look at the other side of the coin!  Think interface contract.  The abstract base class is NOT defining any default implementation for you.  Now, when you browse the abstract class you can SEE the member methods that are or not implemented without having to look any further.  Also, when the members of the abstract class are declared as abstract the IDE can generate method stubs for you automatically!  That does not happen if they are declared as virtual.

    Mark the best replies as answers. Fooling computers since 1971.

  • RELEVANCY SCORE 3.82

    DB:3.82:Diference Between Abstract Class And Interface cp



     
    Hi,
     
    I had a doubt on basic concept of interface and abstract class.
     
    I had idea of wht is interface and abstract class but there is case ,can any do justification on these case is
     
    Abstract class is a clas where some methods r defined and some are abstract methods.
    Interface is where all methods are abstract .
     
    but what happen if i try to maintaince all methods in abstract class as abstract which is equivalent to interface.?
     
    We go for abstract class if want to extend functionality of class.For interface if we wanna implement a new implementation.
     
    is there any other difference apart from this and other issues if we try to have all methods abstract .
     
     
    With regards
    Mahender

    DB:3.82:Diference Between Abstract Class And Interface cp

    Hi,
     
    Thnx for giving info.Actually iam looking for projct development point of view..In whihc cases i do go 4 developing abstract classes  other interfaces

  • RELEVANCY SCORE 3.82

    DB:3.82: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 3.80

    DB:3.80:Good Simple Example Of Difference Between Interface And Abstract Class 83


    Hi All,

    I am new to java...

    I am confused lot about the difference between interface and abstract class....

    Can anybody tell me the difference between interface and abstract class with some good and simple exmple...

    Kindly help me...

    Thanks in advance...

    DB:3.80:Good Simple Example Of Difference Between Interface And Abstract Class 83

    phdk wrote:
    georgemc wrote:
    public class AbstractClassThatIsntAnInterface {

    public abstract void doSomething();
    public abstract void doSomethingElse();

    }Nice naming for a nonabstract class! ;-)

    @OP: read this: [http://java.sun.com/docs/books/tutorial/java/IandI/abstract.html]Er, you, um, spotted my deliberate mistake.....

  • RELEVANCY SCORE 3.79

    DB:3.79:Why Interface?Differnce Between Interface And Abstract Class d3


    why we go for interface? what is the difference between interface and abstract class?

    can anyone plz explain with clear picture.

    DB:3.79:Why Interface?Differnce Between Interface And Abstract Class d3

    Look at his profile. He's nothing but a homework dumper anyway. Someone to be ignored.

  • RELEVANCY SCORE 3.79

    DB:3.79: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 3.79

    DB:3.79:Difference Between Inheritance And Abstract Class 9s


    difference between inheritance and abstract class

    DB:3.79:Difference Between Inheritance And Abstract Class 9s

    There was never an episode of Blackadder where he tried to con his aunt out of an abstract class

  • RELEVANCY SCORE 3.79

    DB:3.79:What Is The Diff Between The Interface And Abstract 9x



    hi,

    could u plz explain the diff between the interface and abstract

    clearly.

    DB:3.79:What Is The Diff Between The Interface And Abstract 9x


    Hi Venkat,

    Check this link

    http://mindprod.com/jgloss/interfacevsabstract.html

    Thanks,

    Vinay

  • RELEVANCY SCORE 3.79

    DB:3.79:What Is The Diff B/W Abstract Class And An Interface ? xd


    Hey

    I am always confused as with this issue : diff b/w Abstract class and an interface ?

    Which is more powerful in what situation.

    Regards
    Vinay

    DB:3.79:What Is The Diff B/W Abstract Class And An Interface ? xd

    Hey

    I am always confused as with this issue: diff b/w Google and forum search ?

    Which is more powerful in what situation.

    Regards
    itchyscratchy

    http://onesearch.sun.com/search/onesearch/index.jsp?charset=UTF-8qt=abstract+interface+differencerf=0rt=1site=devnh=10cs=0col=developer-forumsdftab=siteid%3AjavachooseCat=javaallsubCat=siteid%3Ajava
    http://www.google.co.uk/search?hl=enq=abstract+interface+differencebtnG=Google+Searchmeta=

  • RELEVANCY SCORE 3.79

    DB:3.79:Interface And Abstract Class ad


    Why can't we declare a static method in Interface but it's possible in abstract class?

    DB:3.79:Interface And Abstract Class ad

    Because an interface is simpler than an abstract class.
    Normally you would put a static method like this into a utility class with a private constructor. see the Math class.

  • RELEVANCY SCORE 3.79

    DB:3.79:Abstract Class Inheriting Another Abstract Class ck


    If I have an "Abstract" class that has the following methods:

    Abstract A
    getX();
    abstract getY();
    abstract getXY();And, another "Abstract" class that "INHERITS" A:

    Abstract B extends AWill the "Abstract" methods in class A be ALSO "Abstract" in class B?

    Thanks.

    DB:3.79:Abstract Class Inheriting Another Abstract Class ck

    Think about it: the alternative would be they are no longer abstract methods -- so where did their mystery bodies come from?

  • RELEVANCY SCORE 3.78

    DB:3.78:Public Abstract Interface Filterconfig pf


    public abstract interface FilterConfig

    what is this class actually . is it abstract class or interface?

    DB:3.78:Public Abstract Interface Filterconfig pf

    interfaces are abstract because you cannot
    instantiate them.

    like you cant instantiate a abstract class.It's the other way around. You cannot instantiate them because they're abstract. Only what's fully concrete can be instantiated.

  • RELEVANCY SCORE 3.78

    DB:3.78:Re: Interface m8


    Java Glossary : interface vs abstract class
    Abstract classes vs. interfaces: When does it make sense to choose an abstract class over an interface?
    Abstract classes and interfaces practicum: Move from theory to practice on when to employ abstract classes vs. interfaces
    Tech Tips: ABSTRACT CLASSES VS. INTERFACES

    DB:3.78:Re: Interface m8

    I'm still entertained by the fact that some folks will
    spell out words like "multiple", "inheritance",
    "interface", and "implement", but not "because".

    :o)LOL!

    This kills me - just bcuz.

    %

  • RELEVANCY SCORE 3.78

    DB:3.78:Difference Between Abstract Class And Interface ? fz


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

    DB:3.78: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 3.76

    DB:3.76:Diff Interface And Abstract Class af


    I would like to know difference between Interface and abstract class.

    I know simple differences ... like with iterface u can achieve multiple inheritence and with abstract class can have method definition.

    It is said that with interface u achive less coupling, while its other way with abstract class.

    What exactly does this mean ?? how this is implemented programatically ??

    Cheers,
    Rana

    DB:3.76:Diff Interface And Abstract Class af

    You're not saying this is a reason not to use interfaces, are
    you?I haven't (yet) had this situation happen to me as a result of evolution of my APIs but I would think that's one thing to consider when choosing whether you should go with an abstract class or an interface for a supertype.

  • RELEVANCY SCORE 3.75

    DB:3.75:Dificult To Understand Interface And Abstract Class 98


    - I need explain what is better to use, interface or abstract class to inherit of square/rectangle.
    Example included is appreciated. Thanks.

    DB:3.75:Dificult To Understand Interface And Abstract Class 98

    Thank you for help me.
    Do you have a classe de rectangle and square?

  • RELEVANCY SCORE 3.71

    DB:3.71:When To Use Abstract Class And Interface 3z


    What is the scenario to use abstract class and interface

    DB:3.71:When To Use Abstract Class And Interface 3z

    Read this too, if you have time. :)
    http://java.sun.com/developer/JDCTechTips/2001/tt1106.html#tip2

  • RELEVANCY SCORE 3.69

    DB:3.69:Abstract Class And Interface mc


    From the design perspective what is the difference between Abstract class and Interface.
    If we are providing design, for a system. When should we use abstract class? and when should we use interface.

    DB:3.69:Abstract Class And Interface mc

    And,
    you can only "extends" one abstract class;
    but "implements" several interfaces.

  • RELEVANCY SCORE 3.69

    DB:3.69:Abstract Class And Interface z1


    What is most important thing about abstract class and interface.

    When to use abstract class and interface.

    DB:3.69:Abstract Class And Interface z1

    The interface is like an agreement where the class
    which implements the interface promises to write the
    implementation code for all the functions in the
    interface.Same for an abstract class, only, rather than "all the methods" it's "all the abstract methods." Of course, you could turn around and usethat wording for interfaces too, but in that case it means "all the methods" since interfaces' methods are all abstract.

  • RELEVANCY SCORE 3.68

    DB:3.68:Interfaces And Abstract Classes 8x


    Whats the difference between an interface and an abstract class.

    DB:3.68:Interfaces And Abstract Classes 8x

    Another trait that is often overlooked is that the abstract methods and constants declared in an interface are always public; with abstract classes, you can declare them (package) and protected scope as well.

  • RELEVANCY SCORE 3.68

    DB:3.68:Re: What Is The Difference Between An Interface And An Abstract Class? 1a


    8000 views already wow.

    DB:3.68: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 3.68

    DB:3.68:Diff Between Abstract Class And Interface - Is This A Difference 7m


    This is quite a common topic thats discussed in any java forums . I would like to confirm if asked about the differences , can I say the following?.

    Abstract class can (or not ) have methods in it and it has no use in instantiating it since it has no meaning in instantiation.
    It has to be inherited for use .
    You need to INHERIT to use an abstract class.
    You can have a variable in Abstract class. ( a silly difference )
    Basically u use an abstract class when you want to provide a generalized form of abstraction and leave the implementation task with the inheriting subclass.

    Interface - group of related methods with empty bodies .
    You need to IMPLEMENT to use an interface.
    I dont think you can have a variable in a interface.
    When you want a few classes to use a few methods which you dont want to be included in the class ,then you go for the interface, which makes it easy to just implement and make use of the methods defined in the interface. But the problem with the interface is that, u have to implement all the methods defined in the interface , even if you dont need some of them.

    PLEASE LET ME KNOW IF THE VARIABLE THING IS A REAL DIFFERENCE. .
    I CANNOT HAVE A VARIABLE DECLARED IN MY INTERFACE RIGHT?

  • RELEVANCY SCORE 3.68

    DB:3.68:Abstract Class And Interface 7x


    Hi,
    This is ramana, I got a doubt
    1. I have one interface
    interface Intabs {
    abstract void method1();
    abstract void method2();
    abstract void method();

    }
    2. Iam trying to convert that interface into abstract class like below
    interface Intabs {
    abstract void method1();
    abstract void method2();
    abstract void method();

    }
    3. Again iam trying to extend that abstract class into class like below
    interface Intabs {
    abstract void method1();
    abstract void method2();
    abstract void method();

    }

    Iam getting errors

    Can i do it in multiple steps: Interface------abstract class----- class

    DB:3.68:Abstract Class And Interface 7x

    Cannot reduce the visibility of the inherited method
    from IntabsDerabst1.java
    Right. As mentioned, you can't assign weaker access priveleges to inherited methods. If you define a method as "public void foo() {}", the "foo()" method must have at least public access in all subtypes. In your example, your interface methods are public, but you're trying to give them "package-private" (default) access in the abstract and concrete implementation classes.

    ~

  • RELEVANCY SCORE 3.67

    DB:3.67:Abstract Class Or Interface. Which One Is Better 77


    hai everybody,

    i have a confusion between choosing of abstract class or Interface.

    abstract class Abstra
    {
    public abstract void abst();
    }
    interface Inter
    {
    public abstract void inter();
    }

    looks almost same !!!
    which one of above is better to inherit for a class.
    and more importantly why ?
    Everybody says it's interface....but i dont understand what could be the reason.
    i want to know the reason if interface is better as compare to abstract class.
    why ? why ? why ? why ?

    DB:3.67:Abstract Class Or Interface. Which One Is Better 77

    a very good answer...get to know first of all whats the difference between Abstract class and Interface.

  • RELEVANCY SCORE 3.66

    DB:3.66:Re: Why An Interface Is Used In A Java Program pc


    These are fair comments as per as interface is concern.... we need interface to declare the methods without implementing the methods. Basically interfaces help implementing classes in a organised way.
    Now We got abstract class also, which has got more or less same features like interfaces. In abstract class also we can declare a method without implementation.
    If we use abstract class and extend that abstract class, we don't have implement all the abstract methods in that particular class,which would extend the abstract class, but if we implement an interface in a class, we have to define all the methods with their body. Now, can anyone tell me , in a generic way, when do we use interface and when do we use abstract class. I don't need the differences between abstract class and interface...that i know...thanks in advance
    take it easy
    RD
    l

    DB:3.66:Re: Why An Interface Is Used In A Java Program pc

    For Ex: 5 years down the line, .........I always wondered why it is said "down the
    line" and not up the line.
    What's so downish about the future ?People degrade as the years pass by. :P

  • RELEVANCY SCORE 3.65

    DB:3.65:Diff Between Abstract Class And Final Class dk



    hi,

    I want to know diff between abstrect class and final class.

    Thanks in advance.

    Regards,

    Agalya

    Edited by: agalya devi on May 29, 2008 12:23 PM

    DB:3.65:Diff Between Abstract Class And Final Class dk


    Abstract class can have both abstract or nromal methods. These cannot be instantiated ie we cant create any instance of this class. Here we cant have implementation for abstract methods. We need to inherit this class in tonother then provide the implementation.

    As we can chain upto N levels in inheritance, ie mutlilevel, If we want to stop the further drill down of the inheritance tree. We need to stop the inhertiance from going further, we go for Final class.

    If a class is declared as Final, then i cannot be inherited further. Likewise, if a method is declared as final, then it cant be over ridden ie we cant provide any implementation or it cannt be redefined.

    Encourage me by rewarding points.

    Regards

    Chandralekha

    Edited by: Susheela Chandralekha on Jun 24, 2008 8:46 AM

  • RELEVANCY SCORE 3.64

    DB:3.64:When To Use Abstract Class And Interface? jp


    hi,

    When to use Abstract class and Interface?

    DB:3.64:When To Use Abstract Class And Interface? jp

    Thanks for all, i got some clear idea about when to use interface and abstract class.

  • RELEVANCY SCORE 3.63

    DB:3.63:Diffrence Between A Interface And A Abstract Class? f7



    Hi OO ABAP Gurus

    Please clear below point to me.

    Diffrence between a Interface and a abstract class?

    Many thanks

    Sandeep Sharma..

    DB:3.63:Diffrence Between A Interface And A Abstract Class? f7


    Interface:

    All the methods of the class ARE UNDEFINED. You need to implement the interface in a class and give the method definition now. In other words INTERFACES just have the declarations no definitions.

    Abstract Class:

    All the methods which are defined for the class may have the definition or may not. Say we have 3 methods defined for this particular abstract class but only 2 have the definition and 1 does not have the definition. Then it becomes the abstract class.

    So, every Interface is a abstract class but not every abstract class is interface.

  • RELEVANCY SCORE 3.62

    DB:3.62:Abstract Class And Interface Use 1k


    hi

    i am asking some stupied questions. plz can any one tell me

    1) what is interface and abstract class ? one example?
    2) when do u go for interface and when do u go for abstract class?
    3) what is exact difference between abstraction and encapsulation?

    thanks in advance

    DB:3.62:Abstract Class And Interface Use 1k

    Mahaboob wrote:
    hi

    i am asking some stupied questions.I agree.

    plz can any one tell meHere's a much better idea. You go do some basic research on these questions which have been asked 1,000,000,000 times previously and then tell us what you think. Then we can have a lively discussion about your ideas.

    'kay?

    And just to get you started in the right direction here's something you can review that will answer part of or all of your questions [_http://java.sun.com/docs/books/tutorial/java/index.html_|http://java.sun.com/docs/books/tutorial/java/index.html]

  • RELEVANCY SCORE 3.61

    DB:3.61:When Use The Abstract Class 8d


    Hello Friend,    When  Use The Abstract Class? and When Use InterFace? and Why Use it.Thank's and Regad,Vivek Patil.

    DB:3.61:When Use The Abstract Class 8d

    Hi  I am satisfied with your Response.Now Plz, Tell me  about Interface

  • RELEVANCY SCORE 3.60

    DB:3.60:Abstract Class 13


    Difference between abstract class and interface
    use of abstract class

    DB:3.60: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 3.57

    DB:3.57:Re: Inteface Vs Abstract Class dd


    interfaces are implented, abstract classes are extended. In an interface ther is no code or variables only methods and any class that implements the interface must provide code implementation for all the methods. An abstract class has code. Why you would use them i have no idea or i jsut fogot

    DB:3.57:Re: Inteface Vs Abstract Class dd

    Joshua Bloch has something to say about this... see the book "Effective Java" - one of the best Java books once you no longer consider yourself a beginner

  • RELEVANCY SCORE 3.57

    DB:3.57:Abstract Class Vs Interface 9a


    Can somebody please explain to me why we need both abstract classes and interfaces? Don't they serve almost exactly the same role? Besides syntax and the possibility of implementing multiple interfaces, is the only difference that an abstract class is allowed to have non-abstract methods?

    DB:3.57:Abstract Class Vs Interface 9a

    interfaces also may have variables but they have to be declared final. ???

  • RELEVANCY SCORE 3.57

    DB:3.57:Abstract Class Vs Interface 1x


    Hi I have a small doubt regarding this.
    When can i go for Abstract Class and When can i go for Interface.
    Anybody can help me?

    DB:3.57:Abstract Class Vs Interface 1x

    Hi I have a small doubt regarding this.
    When can i go for Abstract Class and When can i go for Interface.
    Anybody can help me?

  • RELEVANCY SCORE 3.56

    DB:3.56:Urgent Please 81


    Hi,

    What is the diff betw an abstract class and interface and in what situtations can i use abstract class and in what situations can i use interface.
    Please can any one help me.

    DB:3.56:Urgent Please 81

    Thank you very much sir,
    Now you gave nice explanation.
    Now i am clear with interface and abstract class.

    If you don't mind may i ask one more question.

    Please can you tell me

    what is the diff betw HashTable, HashTree and HashMap.

  • RELEVANCY SCORE 3.56

    DB:3.56: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:3.56:Difference 7x

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

    db

  • RELEVANCY SCORE 3.55

    DB:3.55: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:3.55: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 3.54

    DB:3.54:Query Related With Abstract Class And Interface. pf


    Hi Friends,

    I am not able to understand when to use abstract class and when to interface? Could any one explain it with a suitable example.

    Thanks,
    Rakesh

    DB:3.54:Query Related With Abstract Class And Interface. pf

    abstract class you can have abstract methods and you can have your onw methods and it's implementations.

    interface never has implementation of it's methods.

    regards,
    cristian

  • RELEVANCY SCORE 3.52

    DB:3.52: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:3.52: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 3.49

    DB:3.49:Difference Between Pure Abstract Class And Interface? 89


    hi,
    i just want to know the difference between pure abstract class(as same as interface- no implementation of methods) and interface

    Thanks,

    DB:3.49:Difference Between Pure Abstract Class And Interface? 89

    A very nice and detailed article on this code project link (posted by Magnus).

  • RELEVANCY SCORE 3.49

    DB:3.49:Difference B/W Abstract Class And Interface dx


    hi friends,

    can anyone plz divulge the differences between abstract class and interface and under what situations can we use these concepts.

    thanks

    madhusudan.D

  • RELEVANCY SCORE 3.48

    DB:3.48:Java Programming 33


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

    DB:3.48: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 3.48

    DB:3.48:Can Interface Extend Abstract Class? k3


    Can interface extend abstract class?

    I tried to make a interface extend an abstract class but i got an error stating:
    interface expected here.

    Can anyone help me ?

    DB:3.48:Can Interface Extend Abstract Class? k3

    ok, but can an interface implement an abstract class?

    No. An interface provides no implementation whatsoever. An abstract class can implement an interface, but not the other way around.

    http://java.sun.com/docs/books/tutorial/java/concepts/interface.html

    ~

  • RELEVANCY SCORE 3.48

    DB:3.48:Abstract Class z3



    Hi to all,

    can any one tel me what are abstract classes and what hapens if i check the ABSTRACT ckeck box while creating a interface in se24(class builder)?

    Thanks Regards

    Priya

    DB:3.48:Abstract Class z3


    Thanks Matthew .

    Thanks Regards

    Priya

    Edited by: priya latha on Dec 19, 2007 11:43 AM

  • RELEVANCY SCORE 3.48

    DB:3.48:Abstract Class Vs Interface In Term Of Speed pd


    Hi guys,
    I read every whare abstract class are faster then interface because interface require extra in direction. i want to know about how compiler deals with interface and abstract class.
    Thanks

    DB:3.48:Abstract Class Vs Interface In Term Of Speed pd

    hi,gays i think doesn't matter for code speed, we don't live in stone era. The question is what is better solution interface or abstract class.there is my visionThanks in advice

  • RELEVANCY SCORE 3.48

    DB:3.48: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 3.48

    DB:3.48:Difference ???? xz


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

    DB:3.48: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 3.48

    DB:3.48:Abstract Class And Interface 7s


    Hai,

    I want to know In which suituation i want to use abstract class and Interface in My Project

    Regards,
    John Jayaraj,
    +91 9865315105

    DB:3.48:Abstract Class And Interface 7s

    Use abstract classes when you need to evolve a hierarchy from a class with some hard coded methods and parameters that must be available for all it's subclasses, and when you don't need to use polymorphism :

    abstract class Papapa() {
    public SomeType somethingI;
    public SomeType somethingII;

    abstract public void methodI(); // must be implemented at subclasses
    abstract public void methodII();
    public void methodAvaiableForAllClasses() {
    do something;
    // you can call methodI and methodII here
    }
    }

    abstract classes also lets you define global variables to be used (i heard its faster than interfaces too, but I don't know enough about it to confirm).

    Interfaces in the other way around lets you play with polymorphism.

    class XXX implements YYY, ZZZ.
    Remember that in Java you can only extends one class (abstract or not).
    class XXX extends YYY, ZZZ would result in an error.

    A good way to get the felling where to use abstract classes and interfaces is reading the Collection API source code.

  • RELEVANCY SCORE 3.48

    DB:3.48: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:3.48: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 3.48

    DB:3.48:Abstract Class Or Inteface 89


    Pls give me some practical example of choosing among abstract class and interface.

    DB:3.48:Abstract Class Or Inteface 89

    Search these forums using the box on the left. This question is asked about 50 times a week, there are tons of answers around

  • RELEVANCY SCORE 3.48

    DB:3.48:Re: Diff Between Abstract &Amp; Interface. d8


    oh sorry my mistake... i was in stress.. i meant for example JButton.
    Interfaces are used when the classes themselves have nothing to do with each other.. but share similarities.. for example an interface to store an object to a db.
    this can be implemented in a class Cat but also in a class called JFrame.. and i'm sure you agree that a jframe has nothing to do with a cat..

    DB:3.48:Re: Diff Between Abstract &Amp; Interface. d8

    If a class is fully abstract (contains abstract methods and constants only) it becomes an interface, so basically an interface is just a special kind of class. The difference is that an abstract class can contain implementation. This distinction (classes with implementation and interfaces without) was made to give Java multiple inheritance but without some problems associated with it (the so called diamond inheritance problem).

    Both classes (abstract and concrete) and interfaces are used to represent is-a relationships. In my view classes (extends) are best suited for classification relationships. This is when the superclass represents a concept to which the subclasses applies. Interfaces (implements) are best suited for attribution relationships. The interface represents a feature you want to add to a subclass.

    Both extends and implements leads to code reuse but in somewhat different ways. Using extends classes can share implementation. Using implements classes can share common features. Code written against an interface (rather than a specific class) will work with all classes implementing that interface so the code becomes general. A good example is Comparable used by all standard sorting methods in Java. They can sort objects of any class as long as it implement that interface.

    Both classes (abstract and concrete) and interfaces are types so you can declare variables of them.

  • RELEVANCY SCORE 3.47

    DB:3.47:When Should I Use Abstract Class And When I Should I Interfaces x8


    when should we use abstract classes over interface or vice versa;i am getting this question regulary;how should i give proper answer.

    whatever methods we define in abstract class same thing we can do in interfaces;

    so what we can achieve with abstract class;

    with regds
    chaitanya

    DB:3.47:When Should I Use Abstract Class And When I Should I Interfaces x8

    You can implement multiple interfaces. You can only inherit from one abstract class.

    Abstract classes can implement some methods (and define others abstract).

    Abstract classes can have fields that get inherited, interfaces can't.

  • RELEVANCY SCORE 3.47

    DB:3.47:Mdb Abstract Base Class And Ejb3 Annotations 1k



    I have following scenario where my MDB class extends an abstract class which implements the MessageListener interface.
    public abstract class MDBBase implements MessageListener {
    public void onMessage(Message message) {
    ....
    processJob(some-params)
    }
    public abstract void processJob (some-params);
    }

    public class MyMDB extends MDBBase {
    public abstract void processJob (some-params) {

    }
    }

    DB:3.47:Mdb Abstract Base Class And Ejb3 Annotations 1k


    I have following scenario where my MDB class extends an abstract class which implements the MessageListener interface.
    public abstract class MDBBase implements MessageListener {
    public void onMessage(Message message) {
    ....
    processJob(some-params)
    }
    public abstract void processJob (some-params);
    }

    public class MyMDB extends MDBBase {
    public abstract void processJob (some-params) {

    }
    }

  • RELEVANCY SCORE 3.47

    DB:3.47: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:3.47: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 3.47

    DB:3.47:Abstact Class And Interface s9


    Hi,

    Any One Can Let me know the exact diff. Between the Abstract class and Interface.

    With
    BAbu

  • RELEVANCY SCORE 3.46

    DB:3.46:Abstract Class And Interface 3j


    I would covet to recognize at what situation we use abstract class
    and when to use interface?

    With Regards,
    Stalin.G

    DB:3.46:Abstract Class And Interface 3j

    http://www.google.com/search?q=abstract+class+interface+site:forum.java.sun.com

  • RELEVANCY SCORE 3.46

    DB:3.46:Re: Which One Is The Best And Why cs


    But implementing interface is generally more
    difficult than extending (abstract) class, because
    (abstract) class provides more things than
    interface.For a start that is wrong, it depends on the interface/abstract class.

    Secondly implementing is not relivent at all to this.

    DB:3.46:Re: Which One Is The Best And Why cs

    I think when ,
    A obja = new B();
    is used the instance variable and methods will
    not be accessible evia obja.Correct.

    B obja = new B();
    is used the instance variable and methods can
    be accessed via obja , which may involve bit more
    memory usage than the previous case .So its betterUtter BS, sorry. The object still is an instance of B.

    to go for the last case if v dont need B instance
    members not to be accessed.That doesn exist.

    and also if A is implemented by many classes
    in the ejb for bussiness logic purpose , only the
    interface is sent back as return value hiding the
    concrete class (Encapsulation)That is generalization or abstraction, not encapsulation.

    .obviously cannot have
    the concrete class with definition in the calling
    end.Huh?

  • RELEVANCY SCORE 3.45

    DB:3.45:Abstract Class And Interface 33


    When we have got is the interface then do you need is an abstract class? ....since i can divide an abstract class to two one is interface and the other a concrete class.....So where is the exact functionality of an abstract class.
    Why is that a file name should be the same as that of the public class declared in that file?

    DB:3.45:Abstract Class And Interface 33

    Why is that a file name should be the same as that of the public class declared in that file?Because that's what is required by the JVM.

  • RELEVANCY SCORE 3.45

    DB:3.45:Abstract Class Vs Interface 9d


    Hi

    I was just wondering what is the advantage of using an abstract class over interface. In what situation, using an abstract class is more suitable than using interface? and vice versa?

    DB:3.45:Abstract Class Vs Interface 9d

    This question has been asked and answered a million times. For instance, see this thread: http://forum.java.sun.com/thread.jsp?forum=31thread=352322

  • RELEVANCY SCORE 3.45

    DB:3.45:What Is The Different Between Abstract An Interface Class? jf


    what is the different between abstract an interface class?
    and
    What is the different between access specifier of public and friendly.

    DB:3.45:What Is The Different Between Abstract An Interface Class? jf

    what is the different between abstract an interface
    class?interfaces contain only signatures of method you'll have to implement and constant
    whereas abstract classes contains method implemented and/or method non implemented

    What is the different between access specifier of
    public and friendly.the scope of 'friendly' is the package which contains it

  • RELEVANCY SCORE 3.45

    DB:3.45:Abstract Or Interface m8


    when to use abstract keyword and interface keyword.

    DB:3.45:Abstract Or Interface m8

    Don't just sit there mute with an open mouth and a stupid grin on your face expecting to be spoonfed replies you can copy into your homework. At least show a reaction for heavens sake! Anybody hoooooome?

  • RELEVANCY SCORE 3.45

    DB:3.45:Interface Vrs Abstract Class ps


    why would i during design choose for an interface or an abstract class. I cant understand the need for both ?

    To make a class a partially implemented, its has to be abstract.
    I can choose to create a complete Interface heirarchy and simulate the same.........

    Can people clarify why Interface and why abstract.

    Ps: I know difference between both but I want to justify myself why I wud go for abstract class or interface

    Looking for ur inputs

    DB:3.45:Interface Vrs Abstract Class ps

    why would i during design choose for an interface or
    an abstract class.If there was no abstract you would have to use overriding to accomplish the same thing. But abstract is stronger because you clearly state your intention of leaving the implementation to a subclass. Overriding isn't enforced, the subclass always has a choise. In short, using abstract the superclass rules, using overriding the subclass rules.

    So the big deal is when to use abstract and when to use overriding. Interfaces don't have anything to do with that! Interface are used when you want to ensure a class has a certain functionality that is not a natural part of the normal class hierarchy. It's often a common way to access data, like for example iteration.

  • RELEVANCY SCORE 3.45

    DB:3.45:Interface/Abstract Class Explanation? km


    Hi,
    what is abstract class and interface? In which situation we use these ? why we use these? any body explain in detail and with sample

    DB:3.45:Interface/Abstract Class Explanation? km

    http://msdn.microsoft.com/en-us/library/scsyfw1d(v=vs.71).aspx
    Interfaces:
    You have a Business Logic Layer that has classes/objects, and it has reference to a Data Access Layer that has classes/objects that will be called by the BLL objects. The DALclasses/objects can implement an interface, a contract between the called
    and calling objects as to what public properties and methods are exposed on the called object that the calling object can see and use.

    That's what can interface is about.
    http://polymorphicpodcast.com/shows/mv-patterns/
    If you want to see interfaces in action, the view the show on the Presenter and the Service Layer.
    http://www.codeproject.com/Articles/6118/All-about-abstract-classes
    Abstract:
    I have never had to create one, but I have used them in 3rd party frameworks like the CSLA framework that has abstractclasses that can be derived from and used, as base classes.

  • RELEVANCY SCORE 3.44

    DB:3.44: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:3.44:What Is The Difference Between Abstract Class And Interface jf

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

  • RELEVANCY SCORE 3.43

    DB:3.43:Interface 9f


    In which situation u will use an interface and abstract class

    Edited by: sb125 on Nov 16, 2007 3:04 AM

    DB:3.43:Interface 9f

    sb125 wrote:
    In which situation u will use an interface and abstract classHere's a situation in which u will use an interface and an abstract class:

    class u extends AbstractList implements Serializable {
    //functionality
    }

  • RELEVANCY SCORE 3.43

    DB:3.43: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:3.43:Interface And Abstract Class ac

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

  • RELEVANCY SCORE 3.42

    DB:3.42:Best Situation That Describe Difference Between Interface And Abstract c7


    Hi, Please tell me the best example or situation where we should choose interface or abstract class?

    DB:3.42:Best Situation That Describe Difference Between Interface And Abstract c7

    Smiley,
    It is the same as about apples and computers.
    An Interface is a contract, it describes what a class should contain to implement it (and can than be used to to get those members of a class whichfulfillthe contract) but an interface contains no actual implementation.
    An Abstract Class is a class itself which can be (only) inherited used as base for another class, the members and properties of a base class can be used likewise the inheriting class.
    Because of above can an Abstract Class implement an Interface, however an Interface cannot implement an Abstract class.

    Success
    Cor

  • RELEVANCY SCORE 3.42

    DB:3.42:Can Anyone Share The Real Time Example With Explanation For Abstract Class And Interface? kk


    Real time examplefor Abstract class ?

    DB:3.42:Can Anyone Share The Real Time Example With Explanation For Abstract Class And Interface? kk

    Hi
    Actually this is vary old school days debate but in today`s worlds it is of no use ,latest design principles says that Program to Interface
    , Let me explain more

    Abstract Class

    Use abstract class when the entity it represent doesn’t exist in real world , for example Shape itself has no meaning , It is pure conceptual so
    you should go for abstract implementation
    Interface

    It is more restricted form of abstract class and always recommended
    Interface Vs Abstract class

    Use interface when you do not have anything to share in base class Use Abstract class of there are some function that will be share across all derived object Always prefer Interface
    Best design Approach

    Best Design approach is to use mix of both i.e. Interface AbstractConcrete , See the share Example below that is very simplified version.

    Hope it help

    using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Text;
    using Microsoft.Practices.EnterpriseLibrary.Logging;

    namespace LoggerSample
    {
    interface IShape
    {
    void Render();
    }

    abstract class Shape : IShape
    {

    public virtual void Render()
    {
    Console.WriteLine(Default Drawing, Empty Box);
    }
    }

    class Default : Shape
    {
    // No implementation for IShape.Render()
    }
    class Circle : Shape
    {
    public override void Render()
    {
    Console.WriteLine(Drawing Circle);
    }
    }
    class Rectangle : Shape
    {
    public override void Render()
    {
    Console.WriteLine(Drawing Rectangle);
    }
    }
    class Program
    {
    static ListIShape MyShapes = new ListIShape();
    static void Main(string[] args)
    {
    MyShapes.Add((IShape)new Default());
    MyShapes.Add((IShape) new Circle());
    MyShapes.Add((IShape) new Rectangle());
    MyShapes.Add((IShape)new Rectangle());
    MyShapes.Add((IShape)new Rectangle());
    MyShapes.Add((IShape)new Circle());

    RenderMyShapes(MyShapes);

    Console.ReadLine();
    }

    public static void RenderMyShapes(ListIShape MyShapes)
    {
    foreach (IShape shape in MyShapes)
    {
    shape.Render();
    }
    }
    }
    }

  • RELEVANCY SCORE 3.41

    DB:3.41:C#: What Is Difference Between Abstract Class And Interface? How To Decide To Use Which One? 18


    I have been asked a question: how to decide to use Abstract class or Interface?
    We know that the Interface is special Abstract. All definitationsare default public and without implemetion. Classed inherit from interface has to implement all definitions.

    Abstract class does not need to implement all the methods and it can not be instantiated.
    Classes inheritfrom abstract classmay sharecommon logic (properties or methods) with abstract class and also override some methods' behavior.
    How to clearily answer this question? Thx!

    JaneC

    DB:3.41:C#: What Is Difference Between Abstract Class And Interface? How To Decide To Use Which One? 18

    Hello JJChen,
    Interface class can be implement in small units of data but abstraction class can be implemented in large units of data.
    1. Here is explanation of
    Interface class
    2. Here is explained
    Abstraction class.
    3.
    Difference betweenAbstraction andInterface class.
    Hope it will help you a lot.
    thanks,

  • RELEVANCY SCORE 3.39

    DB:3.39:Interface Vs Abstract Class sa


    when would you create an interface as opposed to an abstract class?

    DB:3.39:Interface Vs Abstract Class sa

    An interface solves the problem of multiple inheritance in Java. A class can only extend from one other class, but can implement multiple interfaces. I link to think of extending in a vertical fashion ( among a class hierarchy ), and interfaces in a horizontal fashion ( across classes that may have nothing in common ).

  • RELEVANCY SCORE 3.39

    DB:3.39:Abstract Class With Abstract Methods Only p7


    Hi,

    What if you had an Abstract class with only abstract methods? How would that be different from an interface? In such case which needs to be chosen?
    I know that abstract class without concrete methods may be a design problem and exists very rarely. But if that was the situation , whether we need to go with
    interface or abstract class? Please clarify.

    Thanks.

    DB:3.39:Abstract Class With Abstract Methods Only p7

    EJP wrote:
    Not really. I see the Java API has many ones that both have abstract and concrete methods.The second statement is irrelevant to the first statement. You have misunderstood what you are saying 'not really' to.Sorry, English is not my native language.

  • RELEVANCY SCORE 3.38

    DB:3.38:Make Abstract Class With Interface. 39


    I want to make an abstract class with methods that need interfacing, but I don't want to make an entire other class for the abstract class to implement. Is there any way to make an abstract class and interface combined into one class with no implementations on that class?

    DB:3.38:Make Abstract Class With Interface. 39

    if you want a class with no implementations that what you need is an Interface

  • RELEVANCY SCORE 3.38

    DB:3.38:Abstract Class &Amp; Interface jp


    In which situation we use Abstract Class and in which situation we use Interface?

    DB:3.38:Abstract Class &Amp; Interface jp

    In which situation we use Abstract Class and in which
    situation we use Interface?It's a frequently asked question so search the forums.

    One answer is that from a pure typing perspective it doesn't matter because they're equal. The difference is that an abstract class can carry implementation, something an interface cannot. So pick the abstract class when you consider that beneficial.

  • RELEVANCY SCORE 3.38

    DB:3.38:Difference % Abstract Class And Interface? d3


    Hi,

    I am confused about abstract class and interface. For interface, the subclass has to implement all the parent class methods. But, it is no need in abstract class.

    However, in which situation should I use abstract class or interface?

    Thanks for explanation.

  • RELEVANCY SCORE 3.37

    DB:3.37:Why Would You Ever Use An Interface Instead Of An Abstract Class? mz


    With an abstract class, you can have unimplemented methods and then implemented methods. With an interface, you can only have unimplemented methods.

    Can somebody tell me, then, why Joe Doe would want to use an interface over an abstract class?

    DB:3.37:Why Would You Ever Use An Interface Instead Of An Abstract Class? mz

    Can somebody tell me, then, why Joe Doe would want to
    use an interface over an abstract class?The main reason is a limitation in the Java inheritance model namely that you can inherit one class only but as many interfaces as you want. This can be characterized as: single inheritance of implementation but multiple inheritance of type. The latter is considered the most important in OO design so the fact that you can inherit implementation from from one source only isn't that much of a limitation really .

    So to make use of multiple inheritance of type in Java you need to use interfaces (and possibly one class).

  • RELEVANCY SCORE 3.37

    DB:3.37:Help Me Developers On Interface And Abstract Class zz


    Which is better to use and why in an Application.interface and abstract class
    I am confused onthis topic.

    DB:3.37:Help Me Developers On Interface And Abstract Class zz

    @Sethp45:

    When you post code, please use [code] and [/code] tags as described in Formatting Help on the message entry page. It makes it much easier to read and prevents accidental markup from array indices like [i].

  • RELEVANCY SCORE 3.37

    DB:3.37:What Is The Difference Between Abstract Class And Interface ? dd


    Hi,

    Could u plz tell me the difference between Abstract class and Interface?

    Thanks in advance.

    Gopi

    DB:3.37:What Is The Difference Between Abstract Class And Interface ? dd

    Lots.

    An abstract class can contain some method implementations, or indeed all the method implementations. It may contain methods with all the various access modifiers. It cannot be instantiated. A class may inherit from only a single abstract class.

    An interface contains only public method stubs and constants. A class may implement multiple interfaces. An interface cannot (obviously) be instantiated.

    Abstract classes are particularly useful when you need to provide a semi-complete implementation for reuse. Interfaces are used more like types.

    Look at java.util.* for some good examples of the use of both.

  • RELEVANCY SCORE 3.37

    DB:3.37:Abstract Class And Interface 18


    what is the difference between abstract class and interface

  • RELEVANCY SCORE 3.37

    DB:3.37:Diff Between An Array, Vector And Hashtable 1a


    1. What is the diffrence between and Array, Vector and a Hashtable and when is it suggested to use an array or vector, hashtable

    2. What is a diffrence between an abstract class and an interface and when are these to be used.

    appreciate if you please tell me about this :)

  • RELEVANCY SCORE 3.37

    DB:3.37:Difference Between Abstract Class And An Interface c3


    hi all,

    what is the difference between an ABSTRACT CLASS with full of METHOD DEFINITIONS and no implemented methods. AND an interface having the same definitions.

    In which situation we use abstract class and in which situation we use interface.

    what are the benefits.

    Can anybody explain it clearly.

    bye
    -hari

    DB:3.37:Difference Between Abstract Class And An Interface c3

    http://www.google.com/search?q=java+difference+abstract+interfaceTrying to teach a man to fish, are you?

  • RELEVANCY SCORE 3.36

    DB:3.36: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:3.36:Why We Use Interface? c9

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

  • RELEVANCY SCORE 3.36

    DB:3.36:Interface Vs Abstract Class d8


    when do we need interface and when abstract class?

    DB:3.36:Interface Vs Abstract Class d8

    2.All the abstract methods must be overrided and
    implemented by the child class.by definition, you can't override a method that has no implementation

    3.Real Examples:

    when we implement the ActionListener interface for
    Button click event then we have to override the
    actionPerformed method, we dont have any other
    chices, so it is a way of forcing the inherited class
    to override certain methods.as before, we implement an abstract method. you're not forcing an override, this can't be done, nor would it be a good idea. as discussed at length recently :-)

    n java you can see all the classes that starts with
    Abstract is abstract.not so. there's nothing at all to stop you writing a concrete class named AbstractClass

  • RELEVANCY SCORE 3.36

    DB:3.36:About Interface In Java 7z


    what is basic idea behind the interface and abstract class

    DB:3.36:About Interface In Java 7z

    Search in this forum. You will find lot of threads discussing the same topic.

  • RELEVANCY SCORE 3.36

    DB:3.36:Abstract And Interface? cm


    why do we need abstract class?
    why do we need interface in java?

    DB:3.36:Abstract And Interface? cm

    Oh please, do some research of your own.

  • RELEVANCY SCORE 3.35

    DB:3.35:Abstract Class sj


    hello

    why cant we create an object to Abstract class and interface ?
    And if we cant create object how can we can create reference variables to both abstract and interface?

    DB:3.35:Abstract Class sj

    kirn291 wrote:
    how can we can create reference variables to both abstract and interface?I can create a variable of type List (interface), like so

    List _myList = new LinkedList();