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

What is action class, The Action Class is type of the Model and is a wrappe...

The Action Class is type of the Model and is a wrapper around the business logic. The purpose of Action Class is to change the HttpServletRequest to the business logic. To use the

File I/O, Write a program that reads both the girl and boy files into memor...

Write a program that reads both the girl and boy files into memory using arrays. Then, allow the user to input a name. The program should search through both arrays. If there is

Create a program using constructors, Create a program Using Constructors? ...

Create a program Using Constructors? The further program uses the constructor to initialize a car rather than setting the areas directly. class CarTest7 { public static voi

Describe inner classes in java, Describe Inner Classes in java? An inne...

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 {

Synchronization and its importance, What do you mean by synchronization an...

What do you mean by synchronization and its importance?

Please answer this, Assignment Help >> JAVA Programming Learning Outcomes:...

Assignment Help >> JAVA Programming Learning Outcomes: 1. Use different program control statements in a programming language 2. Demonstrate the use of arrays with a programming

Write a xhtml document with java script, Write an XHTML document that uses ...

Write an XHTML document that uses JavaScript code to do the following.  The user is first prompted for a word and then for a possible prefix for that word.  If the prefix is not an

Finding highest and lowest numbers, Hi i need help creating a small program...

Hi i need help creating a small program that basically asks the user how many numbers hes going to use and then ask for those numbers and see which is the biggest and the smaller

Boggle Game, any one out there with Boggle Source code?......i really need ...

any one out there with Boggle Source code?......i really need it guys please.

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