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 static in java, What is static in java? Static means one per cl...

What is static in java? Static means one per class, not one for each object no matter how many example of a class might exist. This means that you can use them without making a

Arithmetic, 1-4 Problem Set: Arithmetic Consider the following statement wh...

1-4 Problem Set: Arithmetic Consider the following statement when responding to questions 1 and 2: Jim develops 5 Java applications a year. Joe develops 10 Java applications a year

Describe the java collections framework? , Comparable interface: The "Com...

Comparable interface: The "Comparable" allows itself to compare with other same types of object. The function compareTo() is specified in the interface. Several of the standa

What is the use of throws keyword, What is the use of throws keyword ? ...

What is the use of throws keyword ? Rather than explicitly catching an exception you can declare in which your method throws the exception. This passes the repsonsibility to h

Explain some advantages of java, Platform independence is the key feature o...

Platform independence is the key feature of Java during runtime. Syntax of java is same to the popular object oriented languages such as C and C++. Java program can eliminate most

What is jms client, An application or procedure that produces and/or receiv...

An application or procedure that produces and/or receives messages.

Explain the reading documentation for a class in the class, Explain the Rea...

Explain the Reading documentation for a class in the class library For instance, let's suppose you need to use the URL class in the java.net package. Through reading the docume

Develop student portal, Develop Student Portal Project Description: T...

Develop Student Portal Project Description: Technology to be used: Java, Portlets, Liferay, functions in Oracle DB, Boostrap. We need develop two pages, a header and foote

Write code in a java for automaton distributed in class, Write a code in a ...

Write a code in a c++/java  for the automaton distributed in the class that accepts keywords(cat,bat,cab). Create an input file along with these words may be two or three copies of

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