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 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

Describe j2ee?, J2EE (Java 2 Enterprise Edition) is an environment for depl...

J2EE (Java 2 Enterprise Edition) is an environment for deploying and developing enterprise applications on various operating system. The J2EE platform consists of J2EE components,

Explain about drawing lines, Explain about Drawing Lines? Drawing strai...

Explain about Drawing Lines? Drawing straight lines along with Java is easy. Just call g.drawLine(x1, y1, x2, y2) where (x1, y1) and (x2, y2) are the endpoints of your lines

Multithreading, For this assignment we will be solving the producer-consume...

For this assignment we will be solving the producer-consumer problem with a bounded buffer. You are required to implement this assignment in Java. There are three components in thi

Object and Instance, What is the difference between instance and object of ...

What is the difference between instance and object of a class? Few says both are same, then why java kept both the words for same thing?

What is arpanet and who developed it, What is ARPANET and who developed it?...

What is ARPANET and who developed it? ARPANET stands for Advanced Research Projects. The initial reasons were to communicate along with and share computer resources between mainl

Convert string to super ascii, A string S is said to be "Super ASCII", if i...

A string S is said to be "Super ASCII", if it contains the character frequency equal to their ascii values. String will contain only lower case alphabets (''''a''''-''''z'''') and

Implement and test a program using java features, This assignment requires ...

This assignment requires you to design, implement and test a program using Java features from the first half of the subject content. You are required to implement in Java all the c

Search on column demonstration in semantic vector, Search on column demonst...

Search on column demonstration in Semantic Vector Project Description: I am preparing a research on Semantic Vectors. But I am not able to check out in a vector representa

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