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 aop alliance, AOP Alliance is an open-source project whose goal is ...

AOP Alliance is an open-source project whose goal is to promote adoption of AOP and interoperability between different AOP implementations by describing a common set of interfaces

Program to calculates the number of unique shapes, 1. Write the code for th...

1. Write the code for the method that calculates the number of unique shapes for a binary search tree with n nodes. Use the formula  where b n is the number of possible sh

Calculate Bill program, Notice that each row now has the type of customer a...

Notice that each row now has the type of customer and the additional data needed. calculateBill remains the same in Customer.  However, the calculateBill in Corporate will add a

Develop an android prize wheel, Project Description: I am seeking someon...

Project Description: I am seeking someone to prepare a small Android app for a promotional offer. It must be designed for use on an Android tablet. Fundamentally, a user will

Java, 1. Which of the following are not valid Java identifiers, and why? (...

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 class Television

Assignment, h there, i want you please to make an full assignment due in Fr...

h there, i want you please to make an full assignment due in Friday :)

How to wrapping your own packages in java, How to Wrapping Your Own Package...

How to Wrapping Your Own Packages in java? Java does not limit you to using just the system supplied packages. You can write your own as well. You write packages just such as

Interfaces and generics, In this assignment, you are provided with an inter...

In this assignment, you are provided with an interface that contains a generic type. You are asked to create two classes that implement this interface. A. The Sequenced Interfac

Diffentiate local and global variables, Diffentiate Local and Global Variab...

Diffentiate Local and Global Variables? Local or function level variable effective just in the function in that they are declared although global variables visible everywhere o

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