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

Difference between pre-emptive scheduling and time slicing, Explain the dif...

Explain the difference between pre-emptive scheduling and time slicing ?

Write a program on filling rectangles, Write a program on Filling Rectangle...

Write a program on Filling Rectangles ? The drawRect() method draws an open rectangle, a box if you prefer. If you need to draw a filled rectangle, use the fillRect() method. O

List the unexpected quotients in java, List the unexpected quotients in jav...

List the unexpected quotients in java? 2/3 = 0 3/2 = 1 1/0 = ArithmeticException 0/0 = ArithmeticException 1.0/0.0 = Inf 1.0/0 = Inf 0.0/0.0 = NaN -1.0/0.0

Polymorphism carbonfootprint interface program, (CarbonFootprint Interface:...

(CarbonFootprint Interface: Polymorphism) Using interfaces, as you learned in this chapter, you can specify similar behaviors for possibly disparate classes. Governments and compan

Online music store application, An online music store offers all songs for ...

An online music store offers all songs for 3$ each. The store requires members to prepay any amount of money they wish, and then download as many songs accordingly. You are require

Difference between static and non-static variable, What is the difference b...

What is the difference between static and non-static variables? A static variable is associated with the class as a whole rather than with specific instances of a class. Non-st

Demonstrate your ability to ability to use java data , Purpose Demonstr...

Purpose Demonstrate your ability to ability to use Java data and control structures. Draw with the aid of conditionals and loops. Background Thought A note on comments:

Explain what is object in java language, Explain what is Object in JAVA lan...

Explain what is Object in JAVA language? They are foundation of object oriented language. They are data structure holds data fields and properties and methods

Concurrent Programming, Problem 1 A savings account object holds a non-nega...

Problem 1 A savings account object holds a non-negative balance, and provides deposit(k ) and withdraw(k ) methods, where deposit(k ) adds k to the balance, and withdraw(k ) subtra

Area under curve, write a program to find the area under thecurve y=f(x)bet...

write a program to find the area under thecurve y=f(x)between x=a and x=b, integrate y=f(x) between the limits of a and b. the area under a curve between two points can be found by

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