Explain subclasses and polymorphism, JAVA Programming

Assignment Help:

Explain Subclasses and Polymorphism ?

Car and Motorcycle are subclasses of MotorVehicle. If you instantiate a Car or a Motorcycle along with new, you can use in which object anywhere you can use a MotorVehicle, since cars are motor vehicles. As same you can use a Motorcycle anywhere you can use a MotorVehicle. This use of a subclass object in place of a superclass object is the starting of polymorphism. I'll say more about polymorphism later.

The converse is not true. While all cars are motor vehicles, not all motor vehicles are cars. A few are motorcycles. Thus if a method expects a Car object you shouldn't provides it a MotorVehicle object instead.

Remember that I said you shouldn't provide a method in which expects a Car a MotorVehicle. I didn't say you couldn't. Objects can be cast into their subclasses. This is useful while using data structures like Vectors that only handle generic objects. It's up to the programmer to remain track of what kind of object is stored in a Vector, and to use it accordingly.

The proper choice of classes and subclasses is a skill learned primarily by experience. There are often different ways to define classes.
toString() as example of polymorphism


Related Discussions:- Explain subclasses and polymorphism

Explain javamail, Normal 0 false false false EN-IN X-...

Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4

Program with fibonacci sequence of first 20 terms, Program 1. Write a J...

Program 1. Write a Java program to display the first 20 Fibonacci numbers Program with Fibonacci sequence of first 20 terms Output 2. Write an applet progr

Area under curve., write a program to find the area under the curve y=f(x) ...

write a program to find the area under the curve y=f(x) between x=a and x=b,integrate y=f(x) between the limits of a and b.   #include float start_point,

Sequence diagrams , Sequence diagrams are communication diagrams which deta...

Sequence diagrams are communication diagrams which detail what messages are sent and when. The sequence diagrams are placed according to time. The time performs as you move from to

Describe member variables vs. local variables, Describe Member Variables vs...

Describe Member Variables vs. Local Variables ? class Car { String licensePlate = ""; // member variable double speed; = 0.0; // member variable double maxSp

Use the constructor, Can we use the constructor, instead of init(), to init...

Can we use the constructor, instead of init(), to initialize servlet? Ans) Yes. Of course you can use the constructor instead of init(). There's nothing to stop you. But you sho

Instance variables and arrays, For an assignment I need to write an array p...

For an assignment I need to write an array program to go along with an instance variable. I keep getting the no main class error when I run my program.

Naive bayes classifier to compute the class of handling, 1) Categorical var...

1) Categorical variable tread Pattern = {A, B} and numerical variable tread Depth are used to classify Handling = {good, poor} of a vehicle. Depth is normally distributed with mean

Methods in java, public class Foothill {    public static void main(String[...

public class Foothill {    public static void main(String[] args)    {       Client person_1 = new Client("Bruce Ruprecht", 16000, 10);       Writer writer_1 = new Writer("Adam Buf

Applying java if and if..else statements, For this Assignment, submit the f...

For this Assignment, submit the following program: Create an application for an animal-fur trimming service. The business is open 15 weeks of the year, from April through July. The

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