Illustrate inheritance and composition?, JAVA Programming

Assignment Help:

The 'is a' relationship is used with inheritance and 'has a' relationship is used with composition. Both composition and inheritance allow you to perform sub-objects inside your new class. Two of the main techniques for code reuse are object composition and class inheritance.

378_Untitled.png

 

Inheritance is single-directional. For example man is a human. But human is not a man. Inheritance needs extends key word. Composition: is used when Man has an eye. It is incorrect to say man is an eye. Composition simply defines using instance variables that refer to other objects. The class man will have an instance variable, which refers to an eye object.

 

 Which one to favor, inheritance or composition? The guide is that inheritance could be only used when subclass 'is a' superclass.

1. Don't use inheritance just to get programming code reuse. If there is no 'is a' relationship then require composition for code reuse. Overuse of implementation inheritance will divide all the subclasses, if the superclass is changed.

 

2. Do not add inheritance just to get polymorphism. If there is no 'is a' relationship and all you need is polymorphism then use interface inheritance with composition, which provides you code reuse.

 


Related Discussions:- Illustrate inheritance and composition?

Data structure, consider the file name cars.text each line in the file cont...

consider the file name cars.text each line in the file contains information about a car ( year,company,manufacture,model name,type) 1-read the file 2-add each car which is represen

Write a bouncing ball game, Write a bouncing ball video game. The game is s...

Write a bouncing ball video game. The game is similar to the one described and depicted in Figure of the text book. The balls bounces within the screen where the two horizontal wal

What is significance of jsf- spring integration, Spring - JSF integration i...

Spring - JSF integration is useful when an event handler wishes to explicitly invoke the bean factory to make beans on demand, such as a bean that encapsulates the business logic t

What are different parts of autowire types, There are four different parts ...

There are four different parts by which autowiring can be done. ? byName ? constructor ? autodetect ? byType

Implement the list calss, Your next task is to implement the MovieList clas...

Your next task is to implement the MovieList class that manages the details for a list of DVD Movies read from the specified data file. The constructor will include a parameter tha

What are the usages of package in java? , It helps to resolve naming confli...

It helps to resolve naming conflicts when different packages have classes with the same names. This also helps you prepare files within your project. As define : java.io package d

While statement in java, The while statement define a loop that iterates as...

The while statement define a loop that iterates as long as condition remains true. In the following instance the control waits till the value of a text field becomes "go":

Derfine j2ee in detail?, A J2EE component is a self-contained functional so...

A J2EE component is a self-contained functional software unit that is assembled into a J2EE application with its related files and classes and interacts with other components. The

What do mean by synchronized and synchronized statements, What do mean by ...

What do mean by synchronized methods and synchronized statements ?

Explain why java does not support multiple inheritance, Question: (a) ...

Question: (a) Differentiate between the following terms using suitable examples of your own:- (i) inheritance v/s composition (ii) subclass v/s superclass (iii) softwa

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