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

Moving test, After refactor the main class to become abstract class, I want...

After refactor the main class to become abstract class, I want to move test method from tset clas of main class to subclass, how to do that?

GUI, I have a GUI assignment due Friday noon and i can''t get my hand on it...

I have a GUI assignment due Friday noon and i can''t get my hand on it will anyone be able to solve it to me and what is the cost?

Explain instance variable, What will be the default values of all the eleme...

What will be the default values of all the elements of an array explained as an instance variable? If the array is an array of primitive types, then all the elements of the arr

Difference between an application server and a web server, An application s...

An application server creates data for a Web server - as, collecting data from databases, processing security checks, applying relevant business programs, and/or storing the state

Test driven development (tdd)? , Test Driven Development (TDD) TDD pro...

Test Driven Development (TDD) TDD process gives your confidence in the delivered code for the following things. 1. TDD can remove duplication of code and also disciplines t

Map objects to a relational database? , Due to impedance mismatch between r...

Due to impedance mismatch between relational technology and object you need to understand the progress of mapping classes (objects) and their relationships to tables and relationsh

Program for sorting algorithm - java program, Introduction: In this pr...

Introduction: In this project, you will explore a few sorting algorithms. You will also test their efficiency by both timing how long a given sorting operation takes and count

Overloaded Methods, QUESTION 3: Overloaded methods Write the overloaded me...

QUESTION 3: Overloaded methods Write the overloaded method named average () for each of the following problems: a) The first method receives THREE (3) integer values and returns

Gen keys, Write a Java class that generates a random integer (between 1 and...

Write a Java class that generates a random integer (between 1 and 250). Call the class GenKeys. GenKeys should have a least one method that returns the integer random number. Gen K

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