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

Can a human doctor be replaced through an expert system, Can a human doctor...

Can a human doctor be replaced through an Expert System? Give reasons to support your answer. Expert System is a computer system that simulates the knowledge and expertise of a

Want an experienced ios and android expert, Want an Experienced iOS and And...

Want an Experienced iOS and Android expert Project Description: I am seeking a super talented team or Individual for a Real Estate app. The project wants to get done in a ver

How does java allocate heap and stack memory?, Each time an object is start...

Each time an object is started in Java it goes into the area of memory named as heap. The primitive variables like double and int are allocated in the stack, if they are local inst

Describe the superclass in inheritance, Describe the Superclass in Inherita...

Describe the Superclass in Inheritance ? In this example you start through defining a more common MotorVehicle class. public class MotorVehicle { private String licensePlat

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

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

Java application game of life, The game of Life, invented by John Conway, i...

The game of Life, invented by John Conway, is supposed to model the genetic laws for birth, survival, and death (see Scienti_c American, October 1970, p. 120). We will play it on a

How many static initializers can there, How many static initializers can yo...

How many static initializers can you have ? As many as you want, but the static initializers and class variable initializers are implemented in textual order and may not refer

What is bean factory, A BeanFactory is like a factory class that having a c...

A BeanFactory is like a factory class that having a collection of beans. The BeanFactory holds Bean Definitions of multiple beans within itself and then instantiates the bean whene

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