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  • Listing 1 . Complete listing for Skins01.mxml.
  • Listing 2 . Beginning of the class named Driver.
  • Listing 3 . The constructor for the Driver class.
  • Listing 4 . The method named buttonHandler.
  • Listing 5 . Beginning of the FancyButton class.
  • Listing 6 . Constructor for the FancyButton class.
  • Listing 7 . The toggleSkin method.
  • Listing 8 . Source code for the file named Skins01.mxml.
  • Listing 9 . Source code for the class named Driver.
  • Listing 10 . Source code for the class named FancyButton.
  • Listing 11 . Source code for the class named ButterflyButton.
  • Listing 12 . Source code for the class named FrogButton.

Supplemental material

I recommend that you also study the other lessons in my extensive collection of online programming tutorials. You will find a consolidated index at www.DickBaldwin.com .

General background information

The first major characteristic of an object-oriented program is encapsulation, which I explained in the previous lesson. The second of the threemajor characteristics is inheritance , followed by polymorphism . I will explain inheritance from a big-picture viewpoint in this lesson and will explain polymorphism in the next lesson.

A new class can extend an existing class

A class can be defined to inherit the properties, events, and methods of another class. From a syntax viewpoint, this is accomplished using the extends keyword.

The class being extended is often called the base class or the superclass , and the new class is often called the derived class or the subclass .

What is inherited?

The subclass inherits the data representation and behavior of the superclass (and all of its superclasses) . However, the subclass can modify the behavior of inherited methods by overriding them. (That will be one of the topics in the next lesson on polymorphism.) The subclass can also add new data representation and behavior that is unique to itsown purposes.

The superclass remains viable

A program can instantiate objects of a superclass as well as from its subclass. From a practical viewpoint, the superclass doesn't even knowthat it has been extended.

A hierarchy of classes

Inheritance is hierarchical. In other words, a class may be the subclass of one (and only one) other class and may be the superclass of one or more other classes.

For example, the ActionScript 3 Button class is a subclass of the UIComponent class, and is the superclass of the following classes:

  • AccordianHeader
  • CheckBox
  • LinkButton
  • PopUpButton
  • RadioButton
  • ScrollThumb
  • SliderThumb

An orderly hierarchy

Inheritance mechanisms allow you build an orderly hierarchy of classes.

When several of your abstract data types have characteristics in common, you can design their commonalities into a single superclass and separate theirunique characteristics into unique subclasses. This is one of the purposes of inheritance. (This purpose is illustrated by the program that I will explain later in this lesson.)

The airship hierarchy

For example, suppose you are building a program dealing with airships. All airships have altitude and range parameters in common. Therefore, you couldbuild a base Airship class containing data and methods having to do with range and altitude.

Questions & Answers

Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
what school?
biomolecules are e building blocks of every organics and inorganic materials.
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
sciencedirect big data base
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
it is a goid question and i want to know the answer as well
characteristics of micro business
for teaching engĺish at school how nano technology help us
Do somebody tell me a best nano engineering book for beginners?
s. Reply
there is no specific books for beginners but there is book called principle of nanotechnology
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
what is the actual application of fullerenes nowadays?
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
Mostly, they use nano carbon for electronics and for materials to be strengthened.
is Bucky paper clear?
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
so some one know about replacing silicon atom with phosphorous in semiconductors device?
s. Reply
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Do you know which machine is used to that process?
how to fabricate graphene ink ?
for screen printed electrodes ?
What is lattice structure?
s. Reply
of graphene you mean?
or in general
in general
Graphene has a hexagonal structure
On having this app for quite a bit time, Haven't realised there's a chat room in it.
what is biological synthesis of nanoparticles
Sanket Reply
Got questions? Join the online conversation and get instant answers!
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Source:  OpenStax, Object-oriented programming (oop) with actionscript. OpenStax CNX. Jun 04, 2010 Download for free at http://cnx.org/content/col11202/1.19
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