Describe inner classes in java, JAVA Programming

Assignment Help:

Describe Inner Classes in java?

An inner class is a class whose body is described inside another class, referred to as the top-level class. For instance:
public class Queue {

Element back = null;

public void add(Object o) {

Element e = new Element();
e.data = o;
e.next = back;
back = e;

}

public Object remove() {

if (back == null) return null;
Element e = back;
while (e.next != null) e = e.next;
Object o = e.data;
Element f = back;
while (f.next != e) f = f.next;
f.next = null;
return o;

}

public boolean isEmpty() {
return back == null;
}

// Here's the inner class
class Element {

Object data = null;
Element next = null;
}

}
Inner classes may also holds methods. They may not contain static members.

Inner classes within a class scope can be public, private, protected, final, abstract.
Inner classes can also be used inside methods, loops, and other blocks of code surrounded by braces ({}). Such a class is not a member, and thus cannot be declared public, private, protected, or static.

The inner class has access to all the methods and fields of the top-level class, even the private ones.
The inner class's short name might not be used outside its scope. If you absolutely must use it, you can use the fully qualified name instead. (For instance, Queue$Element) Therefore, if you require doing this you should almost certainly have made it a top-level class instead or at least an inner class inside a broader scope.

Inner classes are most useful for the adapter classes needed through 1.1 AWT and JavaBeans event handling protocols. They permit you to implement callbacks. In most other languages this would bo done along with function pointers.


Related Discussions:- Describe inner classes in java

Java Gui, Does the java applet using swing components, JAVA Programming on ...

Does the java applet using swing components, JAVA Programming on this contain all the source codes for download?

What is documentation for the class library, What is Documentation for the ...

What is Documentation for the class library Sun gives a large amount of documentation for the classes, interface's and exceptions in the class library. If you've installed the

Program for sorting algorithm - java program, Introduction: In this pr...

Introduction: In this project, you will explore a few sorting algorithms. You will also test their efficiency by both timing how long a given sorting operation takes and count

What restrictions are placed on method overriding, What restrictions are pl...

What restrictions are placed on method overriding? Overridden methods must have the similar name, argument list, and return type. The overriding method may not limit the access

Explain the 4 phases of RUP?, 1. Inception : In the mean while the inc...

1. Inception : In the mean while the inception phase, you work out the business part for the project. You also will be creating a rough cost estimate and return on investment.

What are the steps of working of tcp and ip protocols, What are the steps o...

What are the steps of working of TCP and IP protocols within internet transmission? TCP divide messages in several packets (capsulation) and sent these messages over the internet

Ejb container security?, EJB elements operate inside a container environmen...

EJB elements operate inside a container environment and rely heavily on the container to give security. The four key services needed for the security are: 1. Identification :

Why we avoiding short circuits, Why we Avoiding Short Circuits ? If you...

Why we Avoiding Short Circuits ? If you need all of your boolean expressions evaluated regardless of the truth value of each, then you can use & and | instead of && and ||. The

How is method overriding different from method overloading, How is method o...

How is method overriding different from method overloading? Overriding involves the creation of two or more concepts with the same name and same signature in different classes

What is initializing fields, What is Initializing Fields ? Fields can (...

What is Initializing Fields ? Fields can (and often should) be initialized while they're declared, just like local variables. class Car { String licensePlate = ""; // e.g

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd