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

Write a short Java application that stores words in an Array, Write a short...

Write a short Java application that stores words in an Array or ArrayList. You get to pick the number of words to store. Generate a random number between 0 (inclusive) and the leng

Explain any five buzz words in java, Question 1 Explain any five buzz w...

Question 1 Explain any five buzz words in Java 2 Explain exception classes and also explain common exceptions in java 3 Explain primitive and abstract data type in java

Why we use java as a programming language? , A:Java is a computer language....

A:Java is a computer language. There are some of the reasons which describe:   1. Built-in support for multi-threading, memory management (automatic garbage collection), and

How many iterations would this for loop run for, How many iterations would ...

How many iterations would this ‘for' loop run for? for ( x = 50 ; x document.write ( x ) ; } Answer: 50 iterations

Application of server clustering? , An application server cluster has of a ...

An application server cluster has of a number of application servers loosely coupled on a network. The server group or server cluster is usually distributed over a number of nodes

A simple desktop software, A simple Desktop Software Project Description...

A simple Desktop Software Project Description: We want a tool that could convert Flash Games into HTML5 Files. These are not tedious games, very simple game. I have attached

Jsp retrive data, how to retrive data in one block from database by click ...

how to retrive data in one block from database by click data link in another block

What is spreadsheet and list any two jobs that it can do, What is spreadshe...

What is spreadsheet? List any two jobs that it can do? A spreadsheet is a grid which organizes data within columns and rows. Spreadsheets form it simple to display information,

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