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Answer 12

Listings

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Answers

Answer 12

True.

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Answer 11

True.

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Answer 10

44321

Back to Question 10

Answer 9

True.

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Answer 8

443521

Back to Question 8

Answer 7

True.

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Answer 6

True

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Answer 5

False. The List interface declares the following overloaded versions of the add method but the Collection interface declares only the first one of the two.

  • add(Object o)
  • add(int index, Object element)

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Answer 4

Compiler Error. The method named fillIt receives a reference to an object of the ArrayList class as the interface type Collection , and attempts to call the following overloaded method on that reference:

add(int index, Object element)

However, the Collection interface knows nothing about a method having that signature.

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Answer 3

False. It is necessary for objects to implement the Comparable interface to make them eligible for inclusion in a SortedSet .

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Answer 2

True.

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Answer 1

False. The fact that the location of each element can be controlled in a List is what causes a List to be an ordered collection.

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Complete program listings

Listing 1 . Comparable01.java.
//File Comparable01.java import java.util.*;public class Comparable01{ public static void main(String args[]){ new Worker().doIt();}//end main() }//end class Comparable01class 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 loopSystem.out.println(); }//end doIt()}// end class Worker class Populator{public static void fillIt(Collection ref){ ref.add(0,new MyClass(4));ref.add(1,new MyClass(4)); ref.add(2,new MyClass(3));ref.add(3,new MyClass(2)); ref.add(4,new MyClass(1));}//end fillIt() }//end class Populatorclass MyClass{ int data;MyClass(){ data = 0;}//end noarg constructor MyClass(int data){this.data = data; }//end parameterized constructorpublic String toString(){ return "" + data;}//end overridden toString() }//end MyClass
Listing 2 . Comparable02.java.
//File Comparable02.java import java.util.*;public class Comparable02{ public static void main(String args[]){ new Worker().doIt();}//end main() }//end class Comparable02class 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 loopSystem.out.println(); }//end doIt()}// end class Worker class Populator{public static void fillIt(Collection ref){ ((List)ref).add(0,new MyClass(4));((List)ref).add(1,new MyClass(4)); ((List)ref).add(2,new MyClass(3));((List)ref).add(3,new MyClass(2)); ((List)ref).add(4,new MyClass(1));((List)ref).add(3,new MyClass(5)); }//end fillIt()}//end class populator class MyClass{int data; MyClass(){data = 0; }//end noarg constructorMyClass(int data){ this.data = data;}//end parameterized constructor public String toString(){return "" + data; }//end overridden toString()}//end MyClass
Listing 3 . Comparable03.java.
//File Comparable03.java import java.util.*;public class Comparable03{ public static void main(String args[]){ new Worker().doIt();}//end main() }//end class Comparable03class 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 loopSystem.out.println(); }//end doIt()}// end class Worker class Populator{public static void fillIt(Collection ref){ ref.add(new MyClass(4));ref.add(new MyClass(4)); ref.add(new MyClass(3));ref.add(new MyClass(2)); ref.add(new MyClass(1));}//end fillIt() }//end class populatorclass MyClass{ int data;MyClass(){ data = 0;}//end noarg constructor MyClass(int data){this.data = data; }//end parameterized constructorpublic String toString(){return "" + data; }//end overridden toString()}//end MyClass

Miscellaneous

This section contains a variety of miscellaneous information.

Housekeeping material
  • Module name: Java4070r: Review
  • File: Java4070r.htm
Disclaimers:

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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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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