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

Develop contact list application, Develop Contact list application Proje...

Develop Contact list application Project Description: Prepare a computer application to help employees manage their contact list. Users must be able to store two kinds of con

Java identifiers and variable class, 1. Which of the following are not vali...

1. Which of the following are not valid Java identifiers, and why? (a) wolVes (b) United(there is only one) (c) 87 (d) 5 3 (e) Real ale (f) isFound?by 2. A cla

Why hub is used in networks, Why hub is used in networks? Hub is networ...

Why hub is used in networks? Hub is networking equipment and a device that connects various computers to form a network. In a network the NIC translates the message within elec

Write a program using local variable, Write a program using local variable ...

Write a program using local variable Public void someMethod( ) { int x; //local variable System.out.println(x); // compile time error } - Constructor - Doesn't

Difference b/w redirecting a request and forwarding request, Both function...

Both functions send you to a new resource like JSP, Servlet etc.     Normal 0 false false false EN-US X-NONE X-NONE

Give the details of xml files used in validator framework, Two XML configur...

Two XML configuration files are uses by The Validator Framework validator-rules.xml and validation.xml. The validator-rules.xml shows the standard validation routines, these are re

What is the difference between internet and intranet, What is the differenc...

What is the difference between Internet and Intranet ? Intranet and internet are 2 domains which are extremely a like but frequent segregated in order to manage security. Inter

Use array to store values in a program, 1) Listing of the source code ( nam...

1) Listing of the source code ( named Rainfall.java ) for your program 2) Two sample output/execution/runs of your program Optional Group Work: This assignment may be done in

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