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Default behavior of equals method

The default version of the equals method behaves essentially the same as the == operator.

That is to say, the inherited default version of the equals method will return true if the two objects being compared are actually the sameobject, and will return false otherwise.

As a result, this program displays false.

Overridden equals is required for valid testing

If you want to be able to determine if two objects instantiated from a class that you define are "equal", you must override the inherited equals method for your new class. You cannot depend on the inherited version ofthe equals method to do that job for you.

Overriding may not be easy

That is not to say that overriding the equals method is easy. In fact, it may be quite difficult in those cases where the classdeclares instance variables that refer to other objects. In this case, it may be necessary to test an entire tree of objects for equality.

Back to Question 3

Answer 2

D. false

Explanation 2

Use of the == operator with references to objects

This program illustrates an extremely important point about the use of the == operator with objects and reference variables containing references to objects.

You cannot determine...

You cannot determine if two objects are "equal" by applying the == operator to the reference variables containing references to those objects.

Rather, that test simply determines if two reference variables refer to the same object.

Two references to the same object

Obviously, if there is only one object, referred to by two different reference variables, then it is "equal" to itself.

Objects of same type containing same instance values

On the other hand, two objects of the same type could contain exactly the same data values, but this test would not indicate that they are "equal." (In fact, that is the case in this program.)

So, how do you test two objects for equal?

In order to determine if two objects are "equal", you must devise a way to compare the types of the two objects and actually compare the contents of oneobject to the contents of the other object. Fortunately, there is a standard framework for doing this.

The equals method

In particular, the class named Object defines a default version of a method named equals that is inherited by all other classes.

Class author can override the equals method

The intent is that the author of a new class can override the equals method so that it can be called to determine if two objects instantiated fromthat class are "equal."

What does "equal" mean for objects?

Actually, that is up to the author of the class to decide.

After having made that decision, the author of the class writes that behavior into her overridden version of the method named equals .

Back to Question 2

Answer 1

The answer is True.

Explanation 1

Not much to explain here

There isn't much in the way of an explanation to provide for this program.

Evaluate seven relational expressions

Each of the seven relational expressions in the argument list for the println method is evaluated and returns either true or false as a boolean value.

Concatenate the individual results, separated by a space

The seven boolean results are concatenated, separated by space characters, and displayed on the computer screen.

Brief description of the relational operators

Just in case your aren't familiar with the relational operators, here is a brief description.

Each of these operators returns the boolean value true if the specified condition is met. Otherwise, it returns false.

== Left operand equals the right operand != Left operand is not equal to the right operand <Left operand is less than the right operand <= Left operand is less than or equal to the right operand >Left operand is greater than the right operand >= Left operand is greater than or equal to the right operand

Back to Question 1

-end-

Questions & Answers

where we get a research paper on Nano chemistry....?
Maira Reply
what are the products of Nano chemistry?
Maira Reply
There are lots of products of nano chemistry... Like nano coatings.....carbon fiber.. And lots of others..
learn
Even nanotechnology is pretty much all about chemistry... Its the chemistry on quantum or atomic level
learn
Google
da
no nanotechnology is also a part of physics and maths it requires angle formulas and some pressure regarding concepts
Bhagvanji
Preparation and Applications of Nanomaterial for Drug Delivery
Hafiz Reply
revolt
da
Application of nanotechnology in medicine
what is variations in raman spectra for nanomaterials
Jyoti Reply
I only see partial conversation and what's the question here!
Crow Reply
what about nanotechnology for water purification
RAW Reply
please someone correct me if I'm wrong but I think one can use nanoparticles, specially silver nanoparticles for water treatment.
Damian
yes that's correct
Professor
I think
Professor
Nasa has use it in the 60's, copper as water purification in the moon travel.
Alexandre
nanocopper obvius
Alexandre
what is the stm
Brian Reply
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
Rafiq
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
Damian
How we are making nano material?
LITNING Reply
what is a peer
LITNING Reply
What is meant by 'nano scale'?
LITNING Reply
What is STMs full form?
LITNING
scanning tunneling microscope
Sahil
how nano science is used for hydrophobicity
Santosh
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
Rafiq
what is differents between GO and RGO?
Mahi
what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
Rafiq
if virus is killing to make ARTIFICIAL DNA OF GRAPHENE FOR KILLED THE VIRUS .THIS IS OUR ASSUMPTION
Anam
analytical skills graphene is prepared to kill any type viruses .
Anam
Any one who tell me about Preparation and application of Nanomaterial for drug Delivery
Hafiz
what is Nano technology ?
Bob Reply
write examples of Nano molecule?
Bob
The nanotechnology is as new science, to scale nanometric
brayan
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Damian
Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
Renato
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
?
Kyle
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
Adin
why?
Adin
what school?
Kyle
biomolecules are e building blocks of every organics and inorganic materials.
Joe
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Source:  OpenStax, Object-oriented programming (oop) with java. OpenStax CNX. Jun 29, 2016 Download for free at https://legacy.cnx.org/content/col11441/1.201
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