Objects First with Java: A Practical Introduction Using BlueJ (6th Edition)
6th Edition
ISBN: 9780134477367
Author: David J. Barnes, Michael Kolling
Publisher: PEARSON
expand_more
expand_more
format_list_bulleted
Expert Solution & Answer
Chapter 4, Problem 3E
Explanation of Solution
Given:
MusicOrganizer class.
listFile() method.
removeFile() method.
To find: The result when listFile(0) method is called after removeFile(0) method.
Solution:
Open BlueJ and then open a new project named Music-organizer-v1.
To make the instance of the class MusicOrganizer, right-click on the class MusicOrganizer and select a new MusicOrganizer() of the class MusicOrganizer to make its instance.
The window would up which will ask for the name of the instance.
So, enter the name of the instance as objMusicOrg1 in place of default instance name and click on OK button.
After that, right-click on that instance residing on the object bench and then click on the method addFile() to add some file names to the instance.
A window would show up asking for the name of the file to add it to the collection.
Enter any file name (along with its location) within the text box linked with it and then click on the OK button.
Repeat this procedure two times to add two file names to the collection.
To call listFile(0) and listFile(1) to show the two files, right-click on the instance musicOrg1 of the class MusicOrganizer, and then click on the method listFile().
When the method listFile is called, a window would show up which will ask for the file index. Since we have stored 2 files in the collection and the indexing in any collection starts form 0, starting from 0 the index will end at 1, that is, from 0 to 1...
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
Using the Get-Help cmdlet will show us the help file of a cmdlet or topic. In this case, the Get-EventLog cmdlet. However, it is not showing the information on the parameters. How can we make it show the information on parameters
Implement the "paint fill"feature seen in several picture editing products.To put it another way, if you have a screen (represented by a two-dimensional array of colours), a point, and a new colour, Fill in the surrounding area until the colour shifts away from the original.
What is wrong with the following code? Why? How can you fix it?
// Remove all the books which contain the given keyword in book title public void removeAllBooks(String keyword) {
for(Book b: booksList) {
if (b.getTitle().indexOf(keyword)>=0) { booksList.remove(b);
}
}
}
Chapter 4 Solutions
Objects First with Java: A Practical Introduction Using BlueJ (6th Edition)
Ch. 4 - Prob. 1ECh. 4 - What happens if you create a new MusicOrganizer...Ch. 4 - Prob. 3ECh. 4 - Prob. 4ECh. 4 - Write a declaration of a local variable called...Ch. 4 - Prob. 6ECh. 4 - Write assignments to the library, cs101. and track...Ch. 4 - If a collection stores 10 objects, what value...Ch. 4 - Write a method call using get to return the fifth...Ch. 4 - Prob. 10E
Ch. 4 - Write a method call to add the object held in the...Ch. 4 - Write a method call to remove the third object...Ch. 4 - Suppose that an object is stored at index 6 in a...Ch. 4 - Add a method called checklndex to the...Ch. 4 - Write an alternative version of checkIndex called...Ch. 4 - Rewrite both the 1istFi1e and removeFi1e methods...Ch. 4 - Prob. 17ECh. 4 - Prob. 18ECh. 4 - We know that the first file name is stored at...Ch. 4 - Prob. 20ECh. 4 - Create a MusicOrganizer and store a few file names...Ch. 4 - Create an ArrayList<String> in the Code Pad by...Ch. 4 - If you wish, you could use the debugger to help...Ch. 4 - Challenge exercise The for-each loop does not use...Ch. 4 - Prob. 25ECh. 4 - Prob. 26ECh. 4 - Prob. 27ECh. 4 - Write out the header of a for-each loop to process...Ch. 4 - Suppose we express the first version of the key...Ch. 4 - Write a while loop (for example, in a method...Ch. 4 - Write a while loop to add up the values 1 to 10...Ch. 4 - Write a method called sum with a while loop that...Ch. 4 - Challenge exercise Write a method isPrime (int n)...Ch. 4 - In the findFirst method, the loop's condition...Ch. 4 - Prob. 35ECh. 4 - Have the MusicOrganizer increment the play count...Ch. 4 - Prob. 37ECh. 4 - Prob. 38ECh. 4 - Prob. 39ECh. 4 - Prob. 40ECh. 4 - Complete the numberOfMembers method to return the...Ch. 4 - Prob. 42ECh. 4 - Prob. 43ECh. 4 - Prob. 44ECh. 4 - Challenge exercise Write a method to play every...Ch. 4 - Prob. 46ECh. 4 - Prob. 47ECh. 4 - Add a close method to the Auction class. This...Ch. 4 - Add a getUnsold method to the Auction class with...Ch. 4 - Suppose the Auction class includes a method that...Ch. 4 - Rewrite getLot so that it does not rely on a lot...Ch. 4 - Prob. 52ECh. 4 - Prob. 53ECh. 4 - Prob. 54ECh. 4 - Prob. 55ECh. 4 - Open the products project and complete the...Ch. 4 - Implement the findProduct method. This should look...Ch. 4 - Implement the numberInStock method. This should...Ch. 4 - Prob. 59ECh. 4 - Challenge exercise Implement a method in...Ch. 4 - Java provides another type of loop: the do-while...Ch. 4 - Prob. 85ECh. 4 - Prob. 86ECh. 4 - Find out about Java's switch-case statement. What...
Knowledge Booster
Similar questions
- You are a cyber investigator, your task is to write a python program that can read file signatures from a file and save them into a list. Each file signature is an element of your list. Then, try to find out if there is a JPG file in there. If there is a JPG file, print out a True on screen. (File Signature for JPG file is: FF D8 FF DB) The input file is: FSCS360_Midterm_Exam_Part2.txtarrow_forwardThe code using only the LinkedList doesn't produce the right output now, it gives this again. Refer to image The output should produce the amount made from the shares using only the LinkedList instead of the Hashmap.arrow_forwardWe know that the first file name is stored at index zero in the ArrayList, and the list stores the file names as strings, so could we write the body of listAllFiles along the following lines? System.out.println(files.get(0)); System.out.println(files.get(1)); System.out.println(files.get(2)); etc. How many println statements would be required to complete the method?arrow_forward
- Thank you, it has the correct output now! Last thing, can this be done without using a Hashmap, but instead with the original method of using just the LinkedList in the original question? If so, please provide another solution without using hashmap to see the difference in structure of the code!arrow_forwardThe acclaimed _NumPy_ library, that `Simpy` is inspired by, allows you to use the subscription operator not just to select individual items, but also to filter with a mask. It adds a second usage to the operator, just like you have had two uses of many of the operators above, such as adding two `Simpy`s or a `Simpy` and a `float`. The big idea of the second usage of subscription notation is that if instead of giving an `int` inside the subscription brackets you give a `list[bool]`, the expression will return a new `Simpy` object containing only the _masked_, or filtered, `values`. For example: ~~~python a = Simpy([1.0, 2.0, 3.0, 4.0, 2.0, 1.0]) mask = a > 2.0 print(mask) # Output: [False, False, True, True, False, False] b = a[mask] print(b) # Output: Simpy([3.0, 4.0]) ~~~ The above example did not need to establish a separate variable named `mask`, it only did so to make it obvious what the `mask` values were. More conventionally, the above example would be written in a…arrow_forwardUse the Iterator Pattern: Create a class called Exercise, and then, in its main method, create an ArrayList called stringArrayList. Add the following five strings to stringArrayList: “one”, “two”, ”three”, ”four”, ”five”. Then, use a for loop and the index of stringArrayList to print all these five strings out to the console. 2. For stringArrayList above, can you use an iterator to traverse the five strings inside, without using the index? 3. If change stringArrayList into a TreeSet, how do you traverse the five strings use an iterator? Implement an Iterator: 4. Create a class called StringArray that is able to store a number of String objects. Create an instance variable, String[] values, (internal data storage) of StringArray to store all the strings. 5. Create a constructor for StringArray, which is able to build an object of StringArray using the parameter. public StringArray(String[] values) 6. Make the class StringArray implements Iterable So that it…arrow_forward
- There are still errors in the lexer and shank files. Please fix those errors and make sure there are no errors in any of the files at all. Attached is an image of the error on the lexer file. There is still an error in the creation of the Lexer object in the main method. Lexer.java package mypack; import java.util.HashMap; import mypack.Token.TokenType; public class Lexer { private static final int INTEGER_STATE = 1; private static final int DECIMAL_STATE = 2; private static final int IDENTIFIER_STATE = 3; private static final int SYMBOL_STATE = 4; private static final int ERROR_STATE = 5; private static final int STRING_STATE = 6; private static final int CHAR_STATE = 7; private static final int COMMENT_STATE = 8; private static final char EOF = (char) -1; private static String input; private static int index; private static char currentChar; private static int lineNumber = 1; private static int indentLevel =…arrow_forwardYou are to implement removeHead, and removeTail and you also have to create the following functions (for visual purposes of the detail explanation, header and trailer sentinels are described as h and t respectively): IMPORTANT NOTE: For all the methods that has the pos parameter i.e. addAt, removeAt, move, make sure to access that specified position from whichever is nearer - the head or the tail - similar to what we have done in the get method. Example DoublyLinkedList: h <-> 10 <-> 30 <-> 40 <-> 50 <-> t int add(int num) This will add the element num into the last element of the linked list and return the position of the newly-added element. In the above example, having add(60) will return 5 as it is the fifth position in the list. int remove(int num) This will remove the first instance of the element and return the position of the removed element. In the above example, having remove(40) will return 3 as 40 was the third element in the linked list…arrow_forwardProblemYou want to use a library-level interface to EGADS for gathering entropy or gettingcryptographically strong pseudo-random data. For example, you may need entropyon a system such as Microsoft Windows, where there is no built-in API for getting itarrow_forward
- How do you clear the whole canvas?arrow_forwardCreate a class MapTester (either in your current project or in a new project). In it, use a HashMap to implement a contacts list similar to the one in the example above. (Remember that you must import java.util.HashMap.) In this class, implement two methods: public void enterNumber(String name, String number) and public String lookupNumber(String name) The methods should use the put and get methods of the HashMap class to implement their functionality.arrow_forwardYour task: Remove any word that does not start with a capital letter. For instance, for the input text of "Hello, 2022 world!", we should get "Hello, 2022 !".arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
Database System ConceptsComputer ScienceISBN:9780078022159Author:Abraham Silberschatz Professor, Henry F. Korth, S. SudarshanPublisher:McGraw-Hill Education
Starting Out with Python (4th Edition)Computer ScienceISBN:9780134444321Author:Tony GaddisPublisher:PEARSON
Digital Fundamentals (11th Edition)Computer ScienceISBN:9780132737968Author:Thomas L. FloydPublisher:PEARSON
C How to Program (8th Edition)Computer ScienceISBN:9780133976892Author:Paul J. Deitel, Harvey DeitelPublisher:PEARSON
Database Systems: Design, Implementation, & Manag...Computer ScienceISBN:9781337627900Author:Carlos Coronel, Steven MorrisPublisher:Cengage Learning
Programmable Logic ControllersComputer ScienceISBN:9780073373843Author:Frank D. PetruzellaPublisher:McGraw-Hill Education
Database System Concepts
Computer Science
ISBN:9780078022159
Author:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan
Publisher:McGraw-Hill Education
Starting Out with Python (4th Edition)
Computer Science
ISBN:9780134444321
Author:Tony Gaddis
Publisher:PEARSON
Digital Fundamentals (11th Edition)
Computer Science
ISBN:9780132737968
Author:Thomas L. Floyd
Publisher:PEARSON
C How to Program (8th Edition)
Computer Science
ISBN:9780133976892
Author:Paul J. Deitel, Harvey Deitel
Publisher:PEARSON
Database Systems: Design, Implementation, & Manag...
Computer Science
ISBN:9781337627900
Author:Carlos Coronel, Steven Morris
Publisher:Cengage Learning
Programmable Logic Controllers
Computer Science
ISBN:9780073373843
Author:Frank D. Petruzella
Publisher:McGraw-Hill Education