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(The programs in previous modules that sorted the array did not rearrange the contents of the list. Only the contents of the array were rearranged.)

Thus, the relationship between an element in the list and the index associated with that element can change as a result of the sorting operationshown in Listing 4 .

Following the sort, when an iterator is used to access the elements, the elements will be returned by the iterator in the newly-sorted order.

The Collections class

Despite the similarity of the names, the Collections class is different from the Collection interface. Here is part of what Oracle has to say about the Collections class:

"This class consists exclusively of static methods that operate on or return collections. It contains polymorphic algorithms that operate oncollections, "wrappers", which return a new collection backed by a specified collection, and a few other odds and ends."

The sort method

The Collections class provides a large number of very interesting and useful methods, such as binarySearch , copy , reverse , and reverseOrder . (The reverseOrder method will be examined in the next module.)

One of the static methods of the Collections class is the sort method. One overloaded version of the sort method can be used to sort a list into the natural ordering of its elements. Another overloaded version sorts a list according to the order induced by a Comparator .

Here is part of what Oracle has to say about this second version of the sort method that uses a Comparator :

public static void sort(List list, Comparator c) "Sorts the specified list according to the order induced by the specified comparator. All elements in the list must be mutually comparableusing the specified comparator ...
The specified list must be modifiable, but need not be resizable. This implementation dumps the specified list into an array,sorts the array, and iterates over the list resetting each element from the correspondingposition in the array. This avoids the n2 log(n) performance that would result from attempting to sort a linked list in place."

Also uses an array

I find it interesting that the sort method uses an array as an intermediary in the sorting process. However, the difference between thisapproach and the approach involving arrays shown in previous modules is given by the following excerpt from the above quotation:

"iterates over the list resetting each element from the corresponding position in the array"

In other words, after sorting the array, the sort method uses the sorted results in the array to rearrange the positions of the elements in thelist, resulting in a sorted list.

A flexible approach to sorting

Thus, the sort method of the Collections class can be used to sort the elements in a list using whatever set of comparison rules you programinto the compare method of the Comparator object. Furthermore, it doesn't matter how the list is actually implemented so long as it properlyimplements the List interface.

The Comparator

The code in Listing 5 shows the class from which the Comparator object was instantiated.

Questions & Answers

anyone know any internet site where one can find nanotechnology papers?
Damian Reply
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.
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
for teaching engĺish at school how nano technology help us
Do somebody tell me a best nano engineering book for beginners?
s. Reply
there is no specific books for beginners but there is book called principle of nanotechnology
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?
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
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
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