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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

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
Do somebody tell me a best nano engineering book for beginners?
s. Reply
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?
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
what's the easiest and fastest way to the synthesize AgNP?
Damian Reply
types of nano material
abeetha Reply
I start with an easy one. carbon nanotubes woven into a long filament like a string
many many of nanotubes
what is the k.e before it land
what is the function of carbon nanotubes?
I'm interested in nanotube
what is nanomaterials​ and their applications of sensors.
Ramkumar Reply
what is nano technology
Sravani Reply
what is system testing?
preparation of nanomaterial
Victor Reply
Yes, Nanotechnology has a very fast field of applications and their is always something new to do with it...
Himanshu Reply
good afternoon madam
what is system testing
what is the application of nanotechnology?
In this morden time nanotechnology used in many field . 1-Electronics-manufacturad IC ,RAM,MRAM,solar panel etc 2-Helth and Medical-Nanomedicine,Drug Dilivery for cancer treatment etc 3- Atomobile -MEMS, Coating on car etc. and may other field for details you can check at Google
anybody can imagine what will be happen after 100 years from now in nano tech world
after 100 year this will be not nanotechnology maybe this technology name will be change . maybe aftet 100 year . we work on electron lable practically about its properties and behaviour by the different instruments
name doesn't matter , whatever it will be change... I'm taking about effect on circumstances of the microscopic world
how hard could it be to apply nanotechnology against viral infections such HIV or Ebola?
silver nanoparticles could handle the job?
not now but maybe in future only AgNP maybe any other nanomaterials
I'm interested in Nanotube
this technology will not going on for the long time , so I'm thinking about femtotechnology 10^-15
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Mueller Reply
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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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