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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


Questions & Answers

do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
it is a goid question and i want to know the answer as well
characteristics of micro business
Do somebody tell me a best nano engineering book for beginners?
s. Reply
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
what is the actual application of fullerenes nowadays?
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
Mostly, they use nano carbon for electronics and for materials to be strengthened.
is Bucky paper clear?
so some one know about replacing silicon atom with phosphorous in semiconductors device?
s. Reply
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Do you know which machine is used to that process?
how to fabricate graphene ink ?
for screen printed electrodes ?
What is lattice structure?
s. Reply
of graphene you mean?
or in general
in general
Graphene has a hexagonal structure
On having this app for quite a bit time, Haven't realised there's a chat room in it.
what is biological synthesis of nanoparticles
Sanket Reply
what's the easiest and fastest way to the synthesize AgNP?
Damian Reply
types of nano material
abeetha Reply
I start with an easy one. carbon nanotubes woven into a long filament like a string
many many of nanotubes
what is the k.e before it land
what is the function of carbon nanotubes?
I'm interested in nanotube
what is nanomaterials​ and their applications of sensors.
Ramkumar Reply
what is nano technology
Sravani Reply
what is system testing?
preparation of nanomaterial
Victor Reply
Yes, Nanotechnology has a very fast field of applications and their is always something new to do with it...
Himanshu Reply
good afternoon madam
what is system testing
what is the application of nanotechnology?
In this morden time nanotechnology used in many field . 1-Electronics-manufacturad IC ,RAM,MRAM,solar panel etc 2-Helth and Medical-Nanomedicine,Drug Dilivery for cancer treatment etc 3- Atomobile -MEMS, Coating on car etc. and may other field for details you can check at Google
anybody can imagine what will be happen after 100 years from now in nano tech world
after 100 year this will be not nanotechnology maybe this technology name will be change . maybe aftet 100 year . we work on electron lable practically about its properties and behaviour by the different instruments
name doesn't matter , whatever it will be change... I'm taking about effect on circumstances of the microscopic world
how hard could it be to apply nanotechnology against viral infections such HIV or Ebola?
silver nanoparticles could handle the job?
not now but maybe in future only AgNP maybe any other nanomaterials
I'm interested in Nanotube
this technology will not going on for the long time , so I'm thinking about femtotechnology 10^-15
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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