• RELEVANCY SCORE 5.09

    DB:5.09: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:5.09: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 3.99

    DB:3.99:Abstract Classes And Interfaces? dp




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

    DB:3.99: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 3.98

    DB:3.98:Difference Between Abstract Interface And Normal Interface za




    Hello Friends,

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

    DB:3.98: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 3.84

    DB:3.84: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:3.84: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 This modifier is obsolete and should not be used in new programs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 3.83

    DB:3.83: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:3.83: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 3.69

    DB:3.69:What Is The Difference Between An Abstract And An Interface Class? pk


    can anyone enlighten me on this, what is the difference between an interface and an abstract class? When should i use an interface instead of a class and vice-versa? thanks!

    DB:3.69:What Is The Difference Between An Abstract And An Interface Class? pk

    public class Test extends MyClass implements MyInterface {
    public Test() {
    someAbstractMethod();
    someInterface();
    someMethodInAbstractClass();
    super.someMethodInAbstractClass();
    }
    public static void main(String[] args) {
    Test foo = new Test();
    }
    public void someAbstractMethod() {
    System.out.println("someAbstractMethod() in Test");
    }
    public void someInterface() {
    System.out.println("someInterFace() in Test");
    }
    // public void someMethodInAbstractClass() {
    // System.out.println("someMethodInAbstractClass() in Test");
    // }
    }

    abstract class MyClass {
    public void someMethodInAbstractClass() {
    System.out.println("someMethodInAbstractClass() in MyClass");
    }
    public abstract void someAbstractMethod();
    }
    interface MyInterface {
    public void someInterface();
    }Run once, uncomment code, run again, compare output

  • RELEVANCY SCORE 3.67

    DB:3.67: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:3.67: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 3.65

    DB:3.65:Re: What Is The Difference Between An Interface And An Abstract Class? 1a


    8000 views already wow.

    DB:3.65: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 3.65

    DB:3.65:General p8



    what is the exact difference between reports and sap script?

    DB:3.65:General p8


    Hi

    Reports are for internal purpose though we can develop some user specific functionalities from our report all cannot fullfil the user requirement so reports for internal use and

    Scripts by using this we can interface an user which willbe easily uderstood by each ad every one

    Regards

    Pavan

  • RELEVANCY SCORE 3.55

    DB:3.55: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:3.55: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 3.50

    DB:3.50:Difference Between Data Classes d8



    Hi

    What is the difference between USR and USR1 data classes?

    DB:3.50:Difference Between Data Classes d8


    hey check out this,

    Data class refer to the physical area in which the tables assigned to the data class are stored.

    refer to the link:

    Data class - Delivery class

    data class

    Regards,

    Midhun Abraham

  • RELEVANCY SCORE 3.49

    DB:3.49:Abstract Class And Interface 17



    Please tell me what is Abstract Class and Interface. Please explain with help of simple example and also tell me difference between them.

    DB:3.49:Abstract Class And Interface 17


    hi

    i will suggest u to refer some basic java book , to clear ur basic concept of OOPS , because these principal remain same for all languages that follow OOPS concept .

    and under standing these with java is easier then with ABAP .

    Abstract Class

    class which have atleast 1 method which is declared only , (no definition is given for it in this class is mentioned as Abstract Method )

    and that class is defined as Abstract class

    Interface :

    only declaration of method done here , no method will be defined here , class which will implement this interface will give definition .

    Diff. b/w Abstract Class and Interface :

    ABS Class can have method with there definition , but one method should be there with declartion only.

    Interface will have all method with out definition .

    hpoe this help u .

    reward if helpful.

  • RELEVANCY SCORE 3.49

    DB:3.49: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:3.49: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 3.47

    DB:3.47:What Is The Difference Between Abstract And Interface? zd


    Could some one explain what is the difference between abstract class and interface class.

    Lets say I'm creating class why would I choose abstract over interface?

    THanks.

    DB:3.47:What Is The Difference Between Abstract And Interface? zd

    The difference between abstract classes and interfaces is interfaces are defined methods only. In abstract class methods are derived.

  • RELEVANCY SCORE 3.46

    DB:3.46:Abstract Classes And Interfaces 97


    HiCan anyone explain me the difference betweeen the abstract class and interfaces?What is the use of the interfaces?How can we inherit multiple Interfaces?Can anyone please explain my above questions in simple words.?

    DB:3.46:Abstract Classes And Interfaces 97

    David,You are correct, I did not notice that he was inheriting from the other interfaces. My bad. I should have paid more attention in my answer.Of course, the next step in all of this would be to explain explicitly implementing the interface, and what would happen if IOne and IThree (for example) each had methods named someOperation. But I think the OP is good for now :)ChrisChris Snyder, Stumbling through code one day at a time

    If your question was answered, please mark it.

  • RELEVANCY SCORE 3.46

    DB:3.46: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:3.46: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 3.45

    DB:3.45:Difference Between Inheritance And Abstract Class 9s


    difference between inheritance and abstract class

    DB:3.45: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 3.42

    DB:3.42:Question On Objects And Classes fd


    1)What is the purpose of run-time class and system class

    2)What is the exact difference in between Unicast and Multicast object ? Where we will use ?

  • RELEVANCY SCORE 3.40

    DB:3.40:Difference j9


    difference between abstract class and interface

    DB:3.40: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 3.40

    DB:3.40: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:3.40:Abstract Class And Interface mc

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

  • RELEVANCY SCORE 3.40

    DB:3.40:Difference Between Abstract Class And An Interface 3z


    Hi,
    Can any one pls define that what is exactly difference between an Abstract Class and an Interface? Also I'll appreciate if some one can tell me that what we should prefer to use and why.
    Waiting for reply,
    Pranav

    DB:3.40:Difference Between Abstract Class And An Interface 3z

    Hm, it shows some uses but it (and it's predecessor article) actually don't tell what an abstract class or an interface is (or I overlooked it :-)

    Abstract class
    An abstract class is a class which can be declared and used to derive from, but which is not possible to instantiate.

    Like Animal - there is no animal, but there are Goldfish or Cat. Thus you want no Animal objects roaming your heap but only Goldfish and Cat instances. Still it makes sense to bundle the common features in Animal, and distribute them per inheritance.

    Interface
    While a class allows to group functions and variables into a unit, an interface only allows to group functions.
    Otherwise it is the same, thus can be derived from.

    However it makes no sense to create different instances of this, because you can't seperate them, there is no variable which would hold different state information that could be used for a comparison with nonequal result.

    Java offers the multiple inheritance from interfaces only, not from classes.
    This is a simplification chosen by the language designers to keep the implementation algorithms for the tools, the VM, the memory layout of the VM and perhaps the semantics complexity simple.
    (Java was intended for remote controls and other embedded devices).

    Why is this simpler?
    If A inherits from B and A inherits from C as well.
    Plus B inherits from D, plus C inherits from D,
    then we have no longer a tree/directed acyclic graph,
    but the more general case of a directed graph.

    This makes algorithms more complicated (tree walk is easier than graph walk, where you have keep track of cycles).

    Further instantiation make more trouble.
    An instance of A would contain two instances of D, one along the path A-B-D, and one along the path A-C-D.
    Thus if B,C,D were classes with variables, B-D's variables might be different from C-D's.
    This makes access semantics and storage much more complex.

    Java simplified this problem by avoiding it by just allowing interfaces for B, C, D.
    Calling A-B-D-f() is the same as calling A-C-D-f().

    Regards,
    Marc

  • RELEVANCY SCORE 3.40

    DB:3.40: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:3.40: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 3.40

    DB:3.40:Interfaces Vs Abstract Classes 1d


    Hi All !!!
    Can any body please tell the difference between Interfaces and Abstract Classes in terms of Third Party Convince, Homogenous and HAS-A Relation Ship.
    Regards,

    DB:3.40:Interfaces Vs Abstract Classes 1d

    do your own homework. had you just asked for the differences, you would probably have gotten an answer, but you've just dumped your homework on the forum and said "do this for me" which we won't

    search the forums for this, it's asked almost every day. but those homework questions? that's your own problem

  • RELEVANCY SCORE 3.40

    DB:3.40:Abstract Class &Amp; Interface 17


    What is the difference between Abstract Class and Interface Class? What I understood is both has to be defined in the subclass i.e methods. Apart from that Interface supports multiple inheritance whereas Abstract class doesn't. When both has to be defined in the subclass and interface supports multiple inheritance why we still need Abstract Class.

    Thanks in Advance,
    R.Ravindhran

    DB:3.40:Abstract Class &Amp; Interface 17

    A class can only extend one other class (Abstract or not) but it can implement any number of interfaces.

  • RELEVANCY SCORE 3.38

    DB:3.38: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:3.38: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 3.38

    DB:3.38:Interfaces Vs. Abstract Classes ps


    1) is there a difference between an interface (that has methods to override) and an abstract class?

    2) also what is the purpose of static members, static methods, and static classes??

    3) is there a distinction between an Abstract Data Type and User Defined Data Types?

    DB:3.38:Interfaces Vs. Abstract Classes ps

    Read Core Java Fundamentals Volume 1 by Horstmann Cornell from Sun Micro. Press release.
    Its a must to know them very well from reading it from the above book rather than relying on what you hav learnt from a discussion board. by the way, its just a personal statement, not intended to offend any fellowmates of the discussion board.

    cheers

    -tamoghna

  • RELEVANCY SCORE 3.37

    DB:3.37:Abstract Class And Interface 18


    what is the difference between abstract class and interface

  • RELEVANCY SCORE 3.31

    DB:3.31:Difference Between Different Invokelater() Methods p8


    What is actually the difference between:

    SwingUtilities.invokeLater()
    EventQueue.invokeLater()

    Are there other classes that implements the invokeLater() method?

    DB:3.31:Difference Between Different Invokelater() Methods p8

    Use the frigging source, Luke.

    javax.swing.SwingUtilities:
    public static void invokeLater(Runnable doRun) {
    EventQueue.invokeLater(doRun);
    }

  • RELEVANCY SCORE 3.29

    DB:3.29: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:3.29: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 3.28

    DB:3.28:Concept Of Abstract Class &Amp; Interface fc


    Hi friends,

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

  • RELEVANCY SCORE 3.27

    DB:3.27:Overloading Vs Polymorphism zc


    What is the exact difference between Overloading and Polymorphism?

    DB:3.27:Overloading Vs Polymorphism zc

    shano wrote:
    Thanks, didn't realise that.

    Did a google search and ended up at another thread in this forum, and actually understand the term a bit better than I did beforehand as a result :)Well, to be fair, subtype polymorphism in association with OO, is often called just polymorphism. That's the case in The Java Programming Language for example. Other polymorphisms of the type system, like overloading and generics, aren't explicitly called polymorphisms in that book.

  • RELEVANCY SCORE 3.27

    DB:3.27:Difference Between Abstract Classes And Interfaces And When To Use Each a1


    Hi,
    I want to know the exact implementation differences between an abstract classes and Interfaces.
    When would we use each of them..
    Its seems that each does the same kind of functionality...but we need to just extend an abstract class in one and implement an Interface in another.

    Do let me know.

    Thanks,
    Ravi

    DB:3.27:Difference Between Abstract Classes And Interfaces And When To Use Each a1

    Hi,
    I want to know the exact implementation differences
    between an abstract classes and Interfaces.
    When would we use each of them..
    Its seems that each does the same kind of
    functionality...but we need to just extend an abstract
    class in one and implement an Interface in another.

    Do let me know.

    Thanks,
    RaviHi Ravi,
    A class must be declared abstract if one or more of its method is abstract. In case of an Interface, ALL the methods MUST be abstract. As java does not support multiple inheritence, Interface comes handy. In java, a class cannot extend from more than one class. To incorporate multiple inheritance, one can extend a class from another class and implement interface.

    public TestClass extends AbsClass implements Inter {
    }

    Thanks,
    Hope this helps,
    Karthick

  • RELEVANCY SCORE 3.27

    DB:3.27: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 3.26

    DB:3.26: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:3.26: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 3.23

    DB:3.23:Simple Query ac


    Difference between Abstract class and interface with practical example

    DB:3.23:Simple Query ac

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

  • RELEVANCY SCORE 3.22

    DB:3.22:Static Vs Abstract Classes 17


    Just wondering if anyone knows the difference between static classes and abstract classes.

    How do static methods, static variables work?

    Is there such a thing as an abstract method?

    Thanks

    DB:3.22:Static Vs Abstract Classes 17

    Ok i think its easier to understand if u see some examples:

    abstract class X{
    protected int value;
    public abstract void setValue(int pValue);
    }
    class Y extends X{
    public void setValue(int pValue) {
    this.value=pValue;
    }//each class, which extends x has to implement this method, or the class has to be //declared abstract too
    }
    class Z extends X{
    public void setValue(int pValue) {
    this.value=2*pValue;
    }
    }

    You can use this inheritance-tree as follows:

    public class try {
    public static void main(String[] args) {
    X try=new X() //NOT possible!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
    X try=new Y();
    try.setValue(10); //the value-field of try has the value 10
    try=new Z();
    try.setValue(10); //the value-field of try has the value 20
    }
    }

    The techinque i used above is called "dynamical linking" and is one of the advantages of an objectoriented language.

    The main difference of abstract and static is, that you can't instantiate an abstract class direct.

    A static class or a static method and variables has just one (and only one!!) represantation during runtime. And if you want to change the value of a static variable within a method this method has to be static too.

    Example:
    public class StaticTest {
    static int counter;
    public StaticTest() {
    counter++;
    }
    public static void print() {
    System.out.println(this.counter);
    }
    }
    public class TestClass {
    public static void main(String[] args) {
    StaticTest test;
    for (int i=0;i10;i++) {
    test=new StaticTest();
    }
    StaticTest.print(); //the output would be 10!!!!!!!!!!!!!!
    }

    }

    I hope this helps

  • RELEVANCY SCORE 3.21

    DB:3.21: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:3.21:Please Suggest 7p

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

  • RELEVANCY SCORE 3.21

    DB:3.21:What Is Meant By Abstract Classes? ss


    what is meant by abstract classes?

    DB:3.21:What Is Meant By Abstract Classes? ss

    You might use an abstract class if you had certain common functionality or data that was shared between a lot of classes. This would allow you to avoid having to have lots of redundant code.

    Conceptually, you would generally want the classes to all be the same general kind (or category, if you prefer) of objects.\

    Suppose, for example, you were writing code to deal with different types of cars. You handle 5 different brands of cars. Notice that:
    a) All 5 brands are still cars - they are just specific kinds (instances of or subtypes of) cars.
    b) Chances are, the vast majority of the code for each of the 5 brands is identical. Even though there are lots of kinds of cars with obvious differences, most of them share certain basic similarities. Suppose, for example, your class has 10 methods; 8 of
    them are the same regardless of what type of car it is, and 2 of them depend on the brand. Obviously, you wouldn't want to have to re-type all 8 methods in all 5 classes; that would be painful both during development and during maintenance (what if you change
    7 of them and forget to change the 8th?).
    c) Any car you actually create will be one of the 5 brands. You will never create something that was just a car. If you were to ask someone what brand is your car?, they would always reply with one of the 5 brands; if someone told
    you that their car's brand was Car, chances are you'd point out that that doesn't answer the question and doesn't even make sense. It does, however, make sense to say that a Hyundai Elantra is a car. To represent that, we would make an abstract
    Car class with 5 different classes (one per brand) inheriting from it. This would also allow all of the brands to share the 8 methods that are the same in each; again, we want to put the parts of the code that don't change in the abstract base class and the
    parts that do change in the concrete (non-abstract) classes.

    Another convenient thing that this allows you to do is defer choosing which kind of car you will instantiate. For example,
    Car car = new Hyundai();

    Car car = new Toyota();

    Car car = new Ford();
    are all perfectly legal (assuming that Hyundai, Toyota, and Ford all inherit from Car, which they presumably would in this example). As I mentioned, this is really useful if you aren't sure in advance exactly what kind you want.

  • RELEVANCY SCORE 3.20

    DB:3.20:Abstract Classes kc


    what is the main purpose of abstract classes. why abstract class do not throw exceptions.

    DB:3.20:Abstract Classes kc

    Hi,

    Why are classes implementing EntityBeans defined as Local declared as abstact classes.

    Seetesh

  • RELEVANCY SCORE 3.20

    DB:3.20:What Is The Difference Between Abstract And Concrete Wsdl? ap


    What is the difference between Abstract and concrete WSDL?

    DB:3.20: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 3.18

    DB:3.18: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:3.18:What Is The Difference Between Abstract Class And Interface jf

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

  • RELEVANCY SCORE 3.18

    DB:3.18: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 3.16

    DB:3.16: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:3.16: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 3.13

    DB:3.13:Abstract Classes Vs. Interfaces zd


    Hi,
    I have 2 basic questions that I'd like answers for:
    1) What is the exact difference(s) between abstract classes and interfaces? --
    2) Where are they used, and why are they preferred in their respective areas of usage?
    I've gone through some books (CORE JAVA, THE COMPLETE REFERENCE,etc.) as well as some online documentation (by Bill Venners, Paul Rogers, Peter Kriens, etc.) and I'm stil confused.
    I'd be glad if someone could shed a little light on this with as little ambiguity as possible.
    Thanx a ton!!!!!!!!!
    TheJavaKid

    DB:3.13:Abstract Classes Vs. Interfaces zd

    Hi,
    I have 2 basic questions that I'd like answers for:
    1) What is the exact difference(s) between abstract
    classes and interfaces? -- The first answer gives a good description, but it may be useful to understand the distinction in terms of an example. One class can implement multiple interfaces, that is, present different views on itself to various objects. I might have some GUI class that implemented ActionListener, KeyEventListener, ListSelectionListener etc etc. As such it registers itself with the various "observables" (ie. a JButton, a JTextField and a JList). The JList should no more be able to call keyTyped() than it should any of the other methods on the GUI class - it can only see the view of the class encapsulated by its valueChanged() method. This has advantageous implications for all sorts of things, in particular the authors of javax.swing implemented the Listeners as interfaces (not abstract classes) so that objects could be more than one thing at a time - remember of course that there is no multiple inheritance in Java.

    However, if you are writing an application, you may feel that it violates encapsulation that a single object implements more than one interface and hence may instead define some type as an abstract class, even if the class has no implementation details whatsoever. By this I mean that you may have 2 "types" within your system which you could define as interfaces but of which you would rather restrict users from defining a class that is simultaneously "both" of these things.

  • RELEVANCY SCORE 3.13

    DB:3.13:Interfaces And Abstract Classes 73


    can anyone pls tell me where exactly an abstract class is used and where exactly an interface is to be used.

    i think the main difference between an abstract class and an interface is that an interface will have all the abstract methods whereas an abstract class can have one or more abstract methods--- if i am not wrong.
    anything to add? -- pls let me know on this....

    and also how they might be useful for us....

    DB:3.13:Interfaces And Abstract Classes 73

    The differences are already quoted. In addition of that
    the abstract class will come in the class/system hierarchy, but interface will not.

  • RELEVANCY SCORE 3.13

    DB:3.13:What Are Real Roles And Abstract Roles In The Albpm 6.0? jc


    Hi All,

    what is the difference between the Real role and abstract role? Can we assign a Real role to Abstract role and vice versa?

    Edited by: user10436555 on Dec 17, 2009 2:55 AM

    DB:3.13:What Are Real Roles And Abstract Roles In The Albpm 6.0? jc

    As you are adding roles in Oracle BPM's development environment called Studio, you are adding abstract roles. Each process with Interactive activies can have one or more abstract roles. If you're using Studio for testing, abstract roles are the only thing you need to be aware of. The participants you create in Studio are assigned the roles you added in the processes. When you log into Studio's testing environment, the participant can only perform the Interactive activities in the abstract role(s) you assigned to them in Studio.

    If you're using Oracle BPM's production environment called Enterprise, real roles are mapped (matched) to the abstract roles when you deploy the processes in your project. These real roles are created inside of Enterprise's web based Process Administration application or are automatically created and mapped if you click "Smart publish" when deploying.

  • RELEVANCY SCORE 3.13

    DB:3.13:Difference Between Exipre And Obosolete 79


    Hi ALL,

    WHAT IS THE EXACT DIFFERENCE BETWEEN exipre and obosolete WITH REFERENCE RMAN.

    DB:3.13:Difference Between Exipre And Obosolete 79

    user12009184 wrote:
    HI,

    suppose i kept retantion policy to 1..means if i have taken 2 backups then first become obsolete, means that is no more needed.
    but out of 2 backups, suppose i lost latest backup i have only obsolete backup, so can i use that obsolete backup to recover database.?

    Kindly help.

    Regards,Hi,

    When you run the command:

    report obsolete;It looks at your default retention policy that you set by using CONFIGURE RETENTION POLICY and based on that reports all the obsolete backups and copies that were cataloged. You may also, run the command:

    report obsolete redundancy 5;This would now override the default retention policy and report all the obsolete backups and copies based on this new retention policy.

    Please keep in mind that this will not delete the backups until you explicitly execute the command:

    delete obsolete;So, in your case if you haven't deleted the obsolete backups and you've lost the recent backups then the previously obsolete backups will now become the latest backups, that is, now if you run the command report obsolete it will not return those backups as obsolete. And yes RMAN may use those backups to perform recovery.

    Last but not least, if you've lost the recent backups it is better if you run CROSSCHECK BACKUP so that RMAN can update its catalog for the backups which doesn't exist anymore (expired) and are still there in the catalog. Because in that case RMAN will try to use those backups and will not find them and then start throwing error messages. Although, it will automatically fail over to the old backups its better if we keep RMAN catalog synchronized.

    Have fun!

    Kashif.

  • RELEVANCY SCORE 3.11

    DB:3.11: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:3.11:Interfaces And Abstract Classes fk

    Abstarct class can never be instantiated. Same as interfaces.

    Can be
    subclassed.Same as interfaces.

  • RELEVANCY SCORE 3.11

    DB:3.11:Use Of An Abstract Keyword 37


    Hi all , I want to know about

    1.the usage of an abstract keyword.

    2.Difference between abstract and interface

    3.When to use abstract keyword.

    DB:3.11:Use Of An Abstract Keyword 37

    Hi all , I want to know about Give it a try yourself first, post it here and you get feedback.

  • RELEVANCY SCORE 3.11

    DB:3.11:Difference Between Jdk Ad Sdk mf


    Hi All,

    I have simple query what is the exact difference between SDK ad JDK.

    Thanks,
    Alok

    DB:3.11:Difference Between Jdk Ad Sdk mf

    JDK is simple Java development files
    J2SDK is JDK+SUN Application Server
    J2EE SDK is JDK for J2EE Applications+ Sun Application Server
    JRE- Java Runtime Enviornment needed for the application to run
    JEE Bundle is the Java Enterprise Edition

  • RELEVANCY SCORE 3.11

    DB:3.11:Help Pls! 87


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

    Thanx!

    DB:3.11: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 3.10

    DB:3.10:Interfaces And Abstract Classes 8x


    Whats the difference between an interface and an abstract class.

    DB:3.10: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 3.10

    DB:3.10:Difference Between Interface And Abstract Class zk


    hai

    please tell me what is the difference between interface and abstract class?

    when i want use inteface? when i want use abstrct class?

    give me the simple example for that?......

    DB:3.10:Difference Between Interface And Abstract Class zk

    This thread is moved from "JavaServer Pages (JSP) and JSTL" to here.

  • RELEVANCY SCORE 3.09

    DB:3.09:Java Programming 33


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

    DB:3.09: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 3.09

    DB:3.09:What Is The Exact Difference Between Taxinn Taxinj ? 3a



    HI gurus,

    could you tell me exatc difference

    DB:3.09:What Is The Exact Difference Between Taxinn Taxinj ? 3a


    TAXINJ:

    1. It is Formula Based Tax procedure.

    2. It was most commonly used upto intial phase of R/3 4.7, but the latter implementations were with TAXINN.

    3. Tax Code plays a vital role, as the Tax Rate are maintained in Tax Code.

    4. It is complex compared to TAXINN

    TAXINN:

    1. It is Condition Based Tax procedure.

    2. Tax Code is required to be maintained in Condition Record, if Tax Code is not found in Condition Record, Sales Cycle will go upto billing, but not release to accounting. Hence even a single Tax code may suffice trhe requirement for different Tax rate.

    Regards,

    Rajesh Banka

    Reward points if helpful

  • RELEVANCY SCORE 3.07

    DB:3.07:Looking For Help On Abstract Method f1


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

    DB:3.07: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 3.07

    DB:3.07: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:3.07:Why We Use Interface? c9

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

  • RELEVANCY SCORE 3.07

    DB:3.07:Update z1



    what is the exact difference between update and modify

    DB:3.07:Update z1


    Hi,

    As everybody suggested update will update the dataset if it exists.

    whereas if u use modify it will check if dataset exists it will modify and if dataset doesn't exists then it will create a new one.

    say for e.g

    TAble-ztable

    Sno name age

    1 tushar 18

    update ztable set name = 'prakhar' where sno = 1.

    or

    ztable-sno ='1'.

    ztable-name = 'prakhar'.

    ztable-age = '18'.

    modify ztable.

    Now if you want to update record one use update command or modify statement.Then only difference comes when record doesn't exist then modify will insert a new one.

    say for e.g if we use modify like this instead of above one

    ztable-sno ='2'.

    ztable-name = 'prakhar'.

    ztable-age = '18'.

    modify ztable.

    than table will be.

    dataset -ztable

    Sno name age

    1 tushar 18

    2 prakhar 18

    Please reward points for the same.

    Message was edited by:

    Prakhar Saxena

  • RELEVANCY SCORE 3.05

    DB:3.05:Inner Classes xp



    What is the difference between INNER CLASSES AND NESTED CLASSES In java.

    DB:3.05:Inner Classes xp

    Thank you.
    I still like to emphasise that the class is local to a
    method,But not limited to methods. You can define a local inner class in any block of code.

    I assume
    anonymous classes are not local inner classes.They can be. As soon as you don't give a class a name it's anonymous wherever it is.

    also assume a local inner class must appear in a
    method. Is this true?No, it can appear in constructors and initialization blocks too.

  • RELEVANCY SCORE 3.04

    DB:3.04:Difference Between Stop And Abort 3z



    Hi All,

    What is the exact difference between the options STOP and ABORT with reference to the workflow?

    DB:3.04:Difference Between Stop And Abort 3z


    Stop will kill process immediately

    Abort will kill process after 60 sec.

  • RELEVANCY SCORE 3.04

    DB:3.04: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:3.04: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 3.04

    DB:3.04:Difference ???? xz


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

    DB:3.04: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 3.04

    DB:3.04: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:3.04: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 3.04

    DB:3.04:What Is The Difference Between....... zf


    Hi, all,

    I am new to this java technology.

    I want to know, what are the differences between

    1) Interface and Abstract classes

    2) Implementing and extending a class

    Please help
    Regards
    Ash

    DB:3.04:What Is The Difference Between....... zf

    Hi,

    I am not an expert on Java, but what I know is that if a class is declared as an interface then it means it only provides a set of methods that have no implementations. So another class will implement that interface class by providing implementations to all those methods that are defined in the interface class. And a class can implement many interfaces. On the other hand if a class is declared as an abstract class then it provides methods that may or may not have implementation and another class will extend this abstract class and can override either all or some methods based on its needs. And a class can extend only one class at a time!

    I hope if my explanation is wrong, someone will correct me.

  • RELEVANCY SCORE 3.03

    DB:3.03:What Is The Difference Between Abstract And Interface? d8



    and pls tell me how to know tat

    wen to use static and instance

    DB:3.03: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 3.03

    DB:3.03:Help With Interface And Abstract cs


    Hi all

    what is the difference between an interface and an abstract class??

  • RELEVANCY SCORE 3.02

    DB:3.02:Exact Difference Between Intialcontextfactoryclasses fz


    Hi gurus,
    I want to know what is exact difference between ApplicationClientInitialContextFactory, RMIInitialContextFactory and RMILBInitialContextFactory.

    I would also like to know If I have Stateful Session Bean in clustermode which Context will be useful. And Why do Oracle has 3 different type of InitialContextFactory Classes. Can ApplicationClientInitialContext do same as RMIInitialContext.

    Thanks
    Ritesh

    DB:3.02:Exact Difference Between Intialcontextfactoryclasses fz

    Refer this document for difference and scenario where each Context Factory should be used:
    http://otn.oracle.com/sample_code/tech/java/codesnippet/j2ee/JNDI/content.html

    Chandar

  • RELEVANCY SCORE 3.02

    DB:3.02: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:3.02: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 3.02

    DB:3.02:Performance Difference Between Java.Beans.Expression And Java Reflection xp


    What is the Performance difference between using java.beans.Expression class and Java Reflection classes like Class,Method ??

  • RELEVANCY SCORE 3.02

    DB:3.02:Difference Between Two Classes dx


    What is the difference between GenericServlet and HttpServlet?I want technical details.

    DB:3.02:Difference Between Two Classes dx

    GenericServlet is protocol independent, whereas HttpServlet is protocol dependent .Http servlets overrides doGet and doPost methods. Generic servlet overides service method. In GenericServlets you cannot use Cookies or HttpSession.

    Session tracking and redirection is also not possible.

  • RELEVANCY SCORE 3.02

    DB:3.02:Difference Between Application And Customising Data? xd



    what is the exact difference between application and customising data ie profiles SAP_CUST and SAP_APPL?

  • RELEVANCY SCORE 3.00

    DB:3.00: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 3.00

    DB:3.00:What Is Exact Difference Between Adconfig.Pl And Adconfig.Ah da


    What is exact difference between adconfig.pl and adconfig.ah

    DB:3.00:What Is Exact Difference Between Adconfig.Pl And Adconfig.Ah da


    984197 wrote:

    What is exact difference between adconfig.pl and adconfig.ah
    Please see the following docs, it explains the usage of each file.Using AutoConfig to Manage System Configurations in Oracle E-Business Suite Release 12 (Doc ID 387859.1)Using AutoConfig to Manage System Configurations with Oracle Applications 11i (Doc ID 165195.1)Autoconfig FAQ (Doc ID 218089.1)Note: This is applicable to 11i and R12 so mentioning the EBS version doesn't make a difference.Thanks,Hussein

  • RELEVANCY SCORE 2.98

    DB:2.98:Difference Between Abstraction And Abstract 98


     Could anyone give diffference between abstract and abstraction with example..

    DB:2.98:Difference Between Abstraction And Abstract 98

     senthilkr wrote:

     
    Could anyone give diffference between abstract and abstraction with example..

  • RELEVANCY SCORE 2.97

    DB:2.97:Deciding Factors Between An Abstract Class And An Interface x7


    Hi,
    I have some good experience developing applications, and have started moving from being a developer to being an architect. My question is very simple, but I always find myself confused when deciding between abstract class and an Interface. A couple of the
    differences I know are:
    1. Abstract classes should be used if we know some of the functionality is going to be inherited, and some will be decided by the child classes themselves. Interfaces however dont provide such functionality.
    2. Abstract classes should be used in case we know the child classes in advance e.g. Vehichle can be an abstract class as we know the derived classes will have same functionality.

    My question :
    What factors should I consider when I have to decide between an abstract class and an Interface.
    Thanks
    Vijay KoulThanks Vijay Koul

    DB:2.97:Deciding Factors Between An Abstract Class And An Interface x7

    In my opinion its best to always go with an interface. The reason is that code-reuse through inheritance never works[citation needed][dubious]. Reaching for composition rather than inheritance has always suited me well. Writing a few bridge methods to
    implement an interface is somewhat cumbersome, but (IMO) worth it.

  • RELEVANCY SCORE 2.97

    DB:2.97:Abstract Class 13


    Difference between abstract class and interface
    use of abstract class

    DB:2.97: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 2.96

    DB:2.96:Re: Comparator Object Instantiation 87


    abillconsl wrote:
    Because Comparator is an interface, not a class. What you did the second time around was flesh it out.More precisely, it's because Comparator is abstract (as are all interfaces), and the anonymous inner class is concrete, with implementations for all of Comparator's abstract methods. The exact same behavior occurs with abstract classes, and for the exact same reason. :-)

    DB:2.96:Re: Comparator Object Instantiation 87

    SquareBox wrote:
    If yes, then why do I have to use an anon class to instantiate the Comparator object? Simple answer is: you don't.
    This works too:static final class SeniorityOrder
    implements ComparatorProduct{
    public SeniorityOrder() {}
    public int compare(Product e1, Product e2) {
    return 1;
    }
    };And then whenever you need one, use 'new SeniorityOrder()'. I hope that isn't your actual comparison method though :-).

    Winston

  • RELEVANCY SCORE 2.96

    DB:2.96:Why Abstract Classes? jx


    Hi friends ..I have a doubt about abstract classes,what is the need of them.

    DB:2.96:Why Abstract Classes? jx

    Check [http://java.sun.com/docs/books/tutorial/java/IandI/abstract.html]

  • RELEVANCY SCORE 2.96

    DB:2.96:Can Anyone Knows? 79


    hi please answer this questions, if anyone knows

    a) With C++, object reference counts are frequently used to keep track of
    how many references to an object exist. Is there a need for such a reference
    count for objects with Java? Please explain why or why not.

    b) write a small pure Java program that computes the free disk space
    of every disk drive available to the Java VM.

    c) What is the difference between anonymous and abstract classes? Under what
    circumstances would you be using anonymous classes?

    Thanks

    DB:2.96:Can Anyone Knows? 79


    can you please tell me the solution of second
    problem---That isn't the purpose to these forums - can you please have a go by writing some code first. This way you will get much more useful help.

  • RELEVANCY SCORE 2.96

    DB:2.96:What Is The Main Difference Between Interface And Abstract Class 37


    Hi ,

    Please help on this ..

    Regards,
    vij

    DB:2.96:What Is The Main Difference Between Interface And Abstract Class 37

    All the methods declared inside interface should be abstract

    All the methods declared for an interface are abstract, by definition.

    but in case of abstract class at least one method should be abstract

    No. An abstract class is not required to have any abstract methods. It's not even a "should".

    Abstract class must be extended abstract ()
    methods generally contain only declaration part
    without definition part.
    No "generally" about it, as there are no exceptions. Abstract methods do not have a declared body, by definition.

    ~

  • RELEVANCY SCORE 2.96

    DB:2.96:Difference B/W Abstract Class And Interface mf


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

    Thanks in advance!

    DB:2.96: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 2.96

    DB:2.96:Difference Between Abstract Classes And Interfaces 9p


    I actually wonder about what are the differences between abstract classes and interfaces may somebody give an example code about it?

    and i have one more question how can i use interfaces like multiple inheritance ? i mean when i implement an interface like

    class a extends b implements c,di have to use all c and d methods but what that methods means?
    I mean as i know we cannot make implementations of methods in interfaces
    but for example in runnable interface there is a method like run() and it has been defined somewhere because it knows what to do(i mean when it will run), i just write my code into that method .

    DB:2.96:Difference Between Abstract Classes And Interfaces 9p

    Abstract classes are the classes that act as super
    classes and must be inherited by the derived
    classes.They provide methods to be implemented in the
    derived classes . whereas interfaces are the ones
    that are not inherited but instead implemented in the
    derived classes.Implementing an interface is also inheritance.

  • RELEVANCY SCORE 2.95

    DB:2.95:Why Do We Go For Inner Classes In Java? j1


    why cant we inherit the classes instead of having inner classes.
    what is the exact difference between the inner class and subclass.
    can anyone please explain me with some examples

    DB:2.95:Why Do We Go For Inner Classes In Java? j1

    Ok, you've got me here: can you write a method in your Moon class,
    say, 'Star getStar()' without any other modification to the other classes?I thought I could, but when I tried it just now I discovered that I can't. gotcha! ;-)

    I blame my increasing age for my senility.You're being too honest; you could've blamed it on some politicians or
    the weather or your neighbours' kids that keep stomping all over the
    place while screaming on the top of their gawdforsaken lungs or your
    next door neighbour who keeps parking his darned car such that it needs
    three darn parking spaces at the least or those folks down the road
    who always produce that awful stench during dinner time or that stupd
    mailman who can't understand that you definitely don't want all that
    commercial trash in your mailbox or those horrible taxforms that make
    you write down your social security number all over the place again and
    again or all that spam your recieve day after day or or or gasp ... ;-)

    (If it's never been possible to access private members of types in the
    same compilation unit, why were compilation units ever considered useful?)Useful to javac that is ...

    kind regards,

    Jos

  • RELEVANCY SCORE 2.95

    DB:2.95:Difference Between.... dk



    Hi SDNers,

    What is the exact difference between Function module, (internal ) sub routine and external sub routine.

    Thanks in advance.

    Senthil kumar

    DB:2.95:Difference Between.... dk


    Hi Senthil,

    Internal subroutine: Here the source code will be in the same ABAP/4 program.

    Ext subroutine: source code will be in the ABAP/4 program other than the calling procedure..

    In contrast to FM ,subroutines have uniquely defined interface.

    subroutines do not return values nor exceptions..

    subroutines cannot be tested independently...

    FM are stored in the central library..

  • RELEVANCY SCORE 2.95

    DB:2.95: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:2.95: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 2.95

    DB:2.95:Difference Between User Exits And Customer Exits mp


    Hi,can anybody tell me what is the exact difference between user exits and customer exits?

    DB:2.95:Difference Between User Exits And Customer Exits mp

    Hi sudheer kumar These r the main differences between user exits and customer exits 1) user exits r subroutines where as customer exits r function modules 2) user exits r not upgraded where as customer exits r will upgrade 3) customer exits r used for creating and additional fields or menu items to stadard tcode where as user exits r used for enabling or disabling the fields on the standrd screen or concatenating the key fields,it is not used adding an additional componenats to stadard tcode4) customer exits r reusable where as user exits r not reusable.cheers!gyanaraj****Pls reward points if u find this helpful

  • RELEVANCY SCORE 2.95

    DB:2.95:Help! 37


    Hello! Everybody
    I am new to programming
    I am learning java
    i am interested to know the difference between interfaces and abstract classes in java

    DB:2.95:Help! 37

    JavaIsMyThing wrote:
    If you create a class that implements an interface, you are required to supply an implementation for ALL of the methods that are declared in the interface you implement.Not if the class is declared abstract.

    ~

  • RELEVANCY SCORE 2.95

    DB:2.95: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:2.95: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 2.95

    DB:2.95: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:2.95: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 2.95

    DB:2.95: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:2.95: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 2.95

    DB:2.95:Various Data Storage Classes In Cmdb! c9



    Hi folks,

    I was going through Atrium Core Concepts planning guide to understand how various classes store data in CMDB. As per guide we have four classes namely, Regular, Categorization, Abstract and Abstract with data replication. I could not understand the difference between last two.

    It is mentioned that BMC_Memory is a categorization class. What difference would it make had it been a regular class?

    Also how would creating each of these classes impact the underlying DB structure. Can someone please explain with example?

    Regards,

    Vicky

  • RELEVANCY SCORE 2.95

    DB:2.95:Difference Between Abstract Class And Interface 71


    Here is a fresher in Java. Could any body tell me the difference between Abstract Class and Interface. And suppose Abstract class has three methods, in those, two of them are Abstract and one is normal method, and it has been implemented in that class itself. If we extend the Abstract class to our class, do we need to over ride or implement all the methods that are there in the Abstract class or we need to implement only those methods that have been declared as abstract. If it is so, then what is the purpose of implementing non abstract method in the Abstract class.

    Sravan

    DB:2.95:Difference Between Abstract Class And Interface 71

    public abstract class TestAbstract {
    public abstract void method1();
    public abstract void method2();
    public static void method3() {
    // non-abstract method must have a body
    }
    }

    public class TestAbstract2 extends TestAbstract {
    public void method1() {
    // Does not work:
    // Object test = new TestAbstract();
    TestAbstract.method3();
    }
    public void method2() {
    }
    }- you will have to implement all method which are declared as abstract. you do not need to implement method3 in this example., only method1 and method2.
    - an abstract class cannot be instantiated (doesn't work: Object test=new MyAbstractClass())
    - a non-abstract method in an abstract class can be used, if it's a static member.
    - with "extends" you can only have one class, and your class will inherit the members of the superclass
    - with "implements" you can use multiple interfaces, which are only a description of what you have to write yourself...

  • RELEVANCY SCORE 2.95

    DB:2.95:Difference Between Hash Table And Hash Map fa


    Hi......

    What is the exact difference between Hashtable and Hash map?

    DB:2.95:Difference Between Hash Table And Hash Map fa

    See reply #4, and when you revive a thread that already contains all the information you feel compelled to post, please don't. It is a waste of everybody's time.

    And when you do post something new, don't say everything three times.

  • RELEVANCY SCORE 2.94

    DB:2.94:Inherit Abstract Classe fc


    Can anyone show me how to make a class inherit all functionalitied from two difference abstract classes in my progam. thanks

    Jadebui.

    class a extends b ??????????
    {}

    abstract class b
    {}

    abstract class c
    {}

    DB:2.94:Inherit Abstract Classe fc

    if you want to declare both classes(b and c) as abstract you can not do multiple inheritances, try this way

    class a extends b{

    }

    abstract class b extends c{

    }

    abstract class c{

    }or you have to decide to declare one of the abstract classes as an interface

  • RELEVANCY SCORE 2.94

    DB:2.94:Abstract Classes And Interfaces 1k


    What is the difference?

    DB:2.94:Abstract Classes And Interfaces 1k


    Hi Bobby1233

    1.
    Abstract class

    Abstract class is a special class, only cant be instantiate, except that, it has all the features a normal class has. A abstract class could contain abstract
    method and this feature doesnt contained by the normal class. If a class derived from an abstract class, it must override the abstract method which declared in the abstract class. An abstract class can also derived from another abstract class, it could
    override the super classs abstract method or not, if it doesnt override, the derived class must override it.

    2.
    Interface

    The interface couldnt be instantiate, it could contain method declaration, property, indexer and event, they all declared public, a class could inherited
    from many interfaces.

    3.
    The difference

    A class derived from an abstract class should override the virtual method which declared in the super class, but if a class derived from an interface, it must
    realize all the members the interface declared. A class only can derived from one abstract class but it can derived from many interfaces. An abstract is a classs abstraction, but the interface is a behavior standard.

    Theres an analogy can help you understand easily:

    A plane can fly and a bird also can fly, they all inherited a fly interface; A helicopter belong to plane abstract class and a pigeon belong to a
    bird abstract class.

    I wish it could help you!

    Allen Li [MSFT]
    MSDN Community Support | Feedback to us
    Get or Request Code Sample from Microsoft
    Please remember to mark the replies as answers if they help and unmark them if they provide no help.

  • RELEVANCY SCORE 2.94

    DB:2.94:Abstract Vs Interfaces sx


    hi i am looking for the difference between abstract classes and interfaces. i have refered a couple of books but nothing seems to satisfy me. and another thing when to use an abstract class and when to use an interface( other than multiple inheritence)

    thanks

    DB:2.94:Abstract Vs Interfaces sx

    In my opinion, Java sun programmers construct
    abstract classes in order to prevent some of the
    disadvantages of interfaces such that using only
    empty bodied method.It is a joke do not take it serious but it is really true that they construct abstract classes in order to prevent some of the disadvantages of interfaces

  • RELEVANCY SCORE 2.94

    DB:2.94:Bsp Api fj



    Hi All,

    I m very new to SAP OOABAP. i whant to now like Java API , is there any SAP API ?

    is there any link for sap api, so that i can see the All the Classes, Abstract Class, Interfaces.

    plece can any one tell me the difference between JSP BSP ?

    like JSP contain this -JSP Tags

    JSP API

    EL

    JSTL

    what about BSP Contains ?

    Regards

    Naresh

    For helpful answer reward points.

    DB:2.94:Bsp Api fj


    Hi,

    Like I have told you, there is no documentation (that I know of) regrouping all classes and interfaces. Actually, it won't have any sense since, unlike Java, not every thing is a class in ABAP. There are function modules too, which are also part of the ABAP API, and structures that are defined in the Data Dictionary (that you won't find in Java).

    You can see attributes and methods of a class in SE24 transaction, but you will have to know the class name. OBJECT class seems to be an exception, but actually, it is an empty class (no attributes nor methods).

    Depending on your problem, you will have to search SDN or SAP help to find which FM or classes can be used to solve it. There are also example programs that can help.

    Regards,

    Tanguy

  • RELEVANCY SCORE 2.93

    DB:2.93:Regarding Abstract Interface sa


    Hello,What makes the difference between the Normal Interfaces and Abstract Interfaces. Is there any technical differences between these two interfaces.Thank you

    DB:2.93:Regarding Abstract Interface sa

    HIAbstract message interface donu2019t have a direction and arenu2019t implemented in an application system. We use them to define the process signature of an integration process.These are also called as hidden Interfaces.The Message interface is the highest level representation of XML meta data. It has two important attributes: mode (Synchronous or Asynchronous) and direction (inbound or outbound). For Business processes, Abstract interfaces are used; these have a mode, but no direction. oReferences fault message types for exception handlingoContext objects can be assigned.oWSDL representation available for exportoStarting point for Proxy generation (ABAP and Java).cheers

  • RELEVANCY SCORE 2.93

    DB:2.93:Java Interfaces And Abstract Classed fc


    what is the difference between interface and abstract class?

    DB:2.93:Java Interfaces And Abstract Classed fc

    I suggest you try writing some code and see.

  • RELEVANCY SCORE 2.92

    DB:2.92:Difference Between Math And Strictmath? 8x


    What is the difference between these classes? They look the same.

    DB:2.92:Difference Between Math And Strictmath? 8x

    http://java.sun.com/j2se/1.4.1/docs/guide/lang/enhancements-1.3.html

    Classes java.lang.Math and java.lang.StrictMath
    The Java 2 Platform now contains two clases which provide API for performing general numeric operations.
    java.lang.StrictMath - Class java.lang.StrictMath has the same API as old class java.lang.Math, which was present previous versions of the Java platform. Unlike class Math, however, StrictMath is defined to return bit-for-bit reproducible results in all implementations.
    java.lang.Math - Class java.lang.Math provides the same set of API as does class StrictMath. However, unlike some of the numeric functions of class StrictMath, all implementations of the equivalent functions of class Math are not defined to return the bit-for-bit same results, but can vary within specified constraints. This permits better-performing implementations where strict reproducibility is not required.

  • RELEVANCY SCORE 2.92

    DB:2.92:What Is Difference Between Abstraction And Abstract Class ? j3


    What is difference between abstraction and abstract class ?

  • RELEVANCY SCORE 2.91

    DB:2.91:Re: Some Doubts z8


    1. what is the max size that a linked list can holdDepends on the heap size available to your JVM.

    2. clear difference between abstract class and
    interface.Interfaces are pure role specifications (cannot hold any implementations).
    Abstract classes usually consist of default implementations and role specifications.

    3. what is the difference of java.awt package classes
    and javax.swing package classes. why we need of swing.
    also why we need JApplet , rather than Applet ClassSwing is newer and (arguably) better and easier to use.

    DB:2.91:Re: Some Doubts z8

    i am not new....i am working with java for an year...