Objects that subclass the Observable class maintain a list of observers. When anObservable object is updated it invokes the update() method of each of its observers tonotify the observers that it has changed
Latest Answer : Observer observe only those class which are Observable. ...
The List interface provides support for ordered collections of objects.
Latest Answer : The list interface extends Collection and declares the behaviour of a collection that stores a sequence of elements. Elements can be inserted or accessed by their position in the list, using a Zero-based index. Alist may contain duplicate elements. ...
The Iterator interface is used to step through the elements of a Collection.
Latest Answer : Iterator Interface is part of java.util package.It is used to retrive the elements in the collection object one by one.It has methods like hasNext(),next().the iterator interface is obtained by using iterator() on the collection object.and the basic diff ...
The EventObject class and the EventListener interface support event processing.
Latest Answer : Java.util.Event class ...
An anonymous class may implement an interface or extend a superclass, but may not bedeclared to do both.
It must provide all of the methods in the interface and identify the interface in itsimplements clause.
Latest Answer : interface enhance the concepts of inheritence. by calling multiple interfaces to class we can also inherinting more than a class indirectly ...
The event-delegation model has two advantages over the event-inheritance model. First,it enables event handling to be handled by objects other than the ones that generate the events (or their containers).
A Java source code file takes the name of a public class or interface that is defined withinthe file. A source code file may contain at most one public class or interface. If a publicclass or interface
An object reference be cast to an interface reference when the object implements thereferenced interface.
The Map interface replaces the JDK 1.1 Dictionary class and is used associate keys withvalues.
Latest Answer : Hi There, Map is one of the datastuctures provided by Sun.Map is an interface ,it is not extending from Collection interface as like List,Set,Queue does.There are 4 Classes which are implemented the Map interface. HashMap ...
