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2. to cook or not to cook

Mary is a vegetarian.  She only cooks and eats vegetarian food.  John is carnivorous.  He cooks and eats meat!  If Mary wants to eat broccoli and cheese, she can learn how to cook broccoli and cheese.  If she wants corn of the cob, she can learn how to cook corn on the cob.  The same goes for John.  If he wants to eat greasy hamburger, he can learn how to cook greasy hamburger.  If he wants to eat fatty hotdog, he can learn how to cook fatty hotdog.  Every time John and Mary want to eat something new, they can learn how to cook it.  This requires that John and Mary to each have a very big head in order to learn all the recipes.

But wait, there are people out there called chefs!  These are very special kinds of chefs catering only to vegetarians and carnivores.  These chefs only know how to cook two dishes: one vegetarian dish and one meat dish.  All John and Mary have to do is to know how to ask such a chef to cook their favorite dish.  Mary will only order the vegetarian dish, while John will only order the meat dish!

How do we model the vegetarian, the carnivore, the chef, the two kinds of dishes the chef cooks, and how the customer orders the appropriate kind of dish from the chef?

The food

To simplify the problem, let's treat food as String.  (In a more sophisticated setting, we may want to model food as some interface with veggie and meat as sub-interface.)

The food consumers

Vegetarians and carnivores are basically the same animals.  They have the basic ingredients such as salt and pepper to cook food.  They differ in the kind of raw materials they stock to cook their foods and in the way they order food from a chef.  Vegetarians and Carnivores can provide the materials to cook but do not know how to cook!  In order to get any cooked meal, they have to ask a chef to cook for them. We model them as two concrete subclasses of an abstract class called AEater . AEater has two concrete methods, getSalt and getPepper , and an abstract method called order , as shown in the table below.

Top-level abstract definition
public abstract class AEater { public String getSalt() {return "salt"; }public String getPepper() { return "pepper";} /*** Orders n portions of appropriate food from restaurant r. */public abstract String order(IChef r, Integer n); // NO CODE BODY!}
Concrete implementations
public class Vegetarian extends AEater{ public String getBroccoli() {return "broccoli"; }public String getCorn() { return "corn";} public String order(IChef c, Object n) {// code to be discussed later; }} public class Carnivore extends AEater{ public String getMeat() {return "steak"; }public String getChicken() { return "cornish hen";} public String getDog() {return "polish sausage"; }public String order(IChef c, Object n) { // code to be discussed later;} }

The chef

The chef is represented as an interface IChef with two methods, one to cook a vegetarian dish and one to cook a meat dish, as shown in the table below.

Questions & Answers

How we are making nano material?
what is a peer
What is meant by 'nano scale'?
What is STMs full form?
scanning tunneling microscope
what is Nano technology ?
Bob Reply
write examples of Nano molecule?
The nanotechnology is as new science, to scale nanometric
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
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
How can I make nanorobot?
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
how can I make nanorobot?
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
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Source:  OpenStax, Principles of object-oriented programming. OpenStax CNX. May 10, 2013 Download for free at http://legacy.cnx.org/content/col10213/1.37
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