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What is the meaning of the following two images?
These images were inserted here simply to insert some space between the questions and the answers to keep them from being visible on the screen at thesame time.
This image was also inserted for the purpose of inserting space between the questions and the answers.
True.
False. Such an object can contain duplicate values but cannot contain duplicate keys .
False. A SortedMap is a Map that maintains its entries in ascending order, sorted according to the keys' natural ordering, or according to a Comparator provided at the time of the SortedMap creation.
True, in the opinion of this author.
True.
False. The natural ordering of a collection of objects of a given class is determined by the code written into the concrete compareTo method when the compareTo method inherited from the Comparable interface is defined. Objects instantiated from a class that doesn't implement the Comparable interface don't have a natural ordering.
False. The natural ordering of the elements in a collection is the ordering imposed by the objects' own compareTo method.
True.
True.
The program output is the three lines of text shown below (without the bullets) .
True.
False? While it is true that the reverse method of the Collections class reverses the order of the elements in a specified list, the method has a void return type.
False. The reverseOrder method of the Collections class returns a reference to an object of the interface type Comparator .
| Listing 1 . Comparator07.java . |
|---|
//File Comparator07.java
//Copyright 2001, R.G.Baldwinimport java.util.*;
public class Comparator07{public static void main(String args[]){new Worker().doIt();
}//end main()}//end class Comparator07
class Worker{public void doIt(){
Iterator iter;Collection ref;
ref = new ArrayList();Populator.fillIt(ref);
iter = ref.iterator();while(iter.hasNext()){
System.out.print(iter.next() + " ");}//end while loop
System.out.println();Collections.reverse((List)ref);
iter = ref.iterator();while(iter.hasNext()){
System.out.print(iter.next() + " ");}//end while loop
System.out.println();Comparator aComparator= Collections.reverseOrder();
Collections.sort((List)ref, aComparator);iter = ref.iterator();
while(iter.hasNext()){System.out.print(iter.next() + " ");
}//end while loopSystem.out.println();
}//end doIt()}// end class Worker
class Populator{public static void fillIt(Collection ref){
ref.add("Joe");ref.add("Bill");
ref.add("Tom");ref.add("JOE");
ref.add("BILL");ref.add("TOM");
}//end fillIt()}//end class Populator |
This section contains a variety of miscellaneous information.
Financial : Although the Connexions site makes it possible for you to download aPDF file for this module at no charge, and also makes it possible for you to purchase a pre-printed version of the PDF file, youshould be aware that some of the HTML elements in this module may not translate well into PDF.
I also want you to know that, I receive no financial compensation from the Connexions website even if you purchase the PDF version ofthe module.
In the past, unknown individuals have copied my modules from cnx.org, converted them to Kindle books, and placed them for sale onAmazon.com showing me as the author. I neither receive compensation for those sales nor do I know who does receive compensation. If youpurchase such a book, please be aware that it is a copy of a module that is freely available on cnx.org and that it was made andpublished without my prior knowledge.
Affiliation : I am a professor of Computer Information Technology at Austin Community College in Austin, TX.
-end-
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