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Specialized for type MyClass

This Comparator is specialized to compare two objects of the class named MyClass . The first two statements in Listing 6 above confirm that both of the incoming objects are of type MyClass . If either object is not of that type, an exception is thrown.

General behavior of compare method

The general description of the behavior of the compare method as provided by Oracle is shown below:

"Compares its two arguments for order. Returns a negative integer, zero, or a positive integer as the first argument is less than, equal to, orgreater than the second."

Implementation of required behavior

This behavior is accomplished by the code shown in Listing 7 . In this case, the comparison is based solely on the values of the instance variablenamed data in each of the two objects.

Depending on which object contains the larger value in its instance variable, a value of 1 or -1 is returned. If the two values are equal, a value of 0is returned.

(Note that it is up to the author of the compare method to decide what constitutes larger. This gives the author of themethod a great deal of control over the results of a sorting operation.)
Listing 7 . Implementation of required behavior.
if(((MyClass)o1).data<((MyClass)o2).data) return -1;if(((MyClass)o1).data>((MyClass)o2).data) return 1;else return 0; }//end compare()

Other stipulations

The documentation for the compare method contains several other stipulations regarding the behavior of the method. While I believe thatthis version of the compare method meets all of those stipulations, I haven't taken the time to test it fully. Therefore, it is possible that itmay not meet all of the stipulations in terms of its behavior.

The equals method

Every new class inherits a default version of the equals method from the class named Object. Therefore, a new class that implements the Comparator interface already has such a method. The new class is free to override the inherited version, or to simply make use of the inheritedversion. Here is what Oracle has to say on the subject:

"Note that it is always safe not to override Object.equals(Object). However, overriding this method may, in some cases, improve performance byallowing programs to determine that two distinct Comparators impose the same order."

Overridden equals method

I decided, for purposes of illustration, to go ahead and override the equals method. However, my overridden version, as shown in Listing 8 isn't very significant. It simply confirms that an object being comparedfor equality to a Comparator object is instantiated from the same class.

Since the Comparator object doesn't contain any instance variables, there isn't much more to be tested for equality.

Listing 8 . The overridden equals method.
public boolean equals(Object o){ if(!(o instanceof TheComparator))return false; else return true;}//end overridden equals() }//end class TheComparator

The program output

Finally, the code shown in Listing 9 uses an Iterator to display the contents of the populated TreeSet object.

Questions & Answers

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
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
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
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
research.net
kanaga
sciencedirect big data base
Ernesto
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
Bharti
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
Daniel
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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