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
Concept explainers
Textbook Question
Chapter 4, Problem 41E
Complete the numberOfMembers method to return the current size of the collection. Until you have a method to add objects to the collection, this will always return zero, of course, but it will be ready for further testing later.
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solutionStudents have asked these similar questions
An alternative approach to creating your methods is to use heredocs.
Create one more method in the Starship class:
encounter(self, enemy_ship)
This method takes in self, along with another Starship object.
The method should simulate a battle between the two ships.
How the method is implemented is almost entirely up to you. You could take in user input for each crew member, or have them each act randomly from the available options, or specify exactly what a given crew member of each type should do. The only requirements are as follows:
Each crew member on each ship should get at least one “turn” before the battle is complete.
If the crew member is Injured on their turn, they should do nothing.
You may assume that each ship will have at least one crew member uninjured when the encounter begins.
You shouldn’t make any assumptions about how many crew members there will be on a given ship, where they will start, or about which subclasses will be present - it’s possible that you’ll have test cases including a ship with no captain, or no doctor.…
Challenge exercise Create a class called SortingTest. In it, create a method that accepts an array of int values as a parameter and prints the elements sorted out to the terminal (smallest element first).
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...
Additional Engineering Textbook Solutions
Find more solutions based on key concepts
Freezing and Boiling Points The following table lists the freezing and boiling points of several substances. Su...
Starting Out with C++ from Control Structures to Objects (8th Edition)
Write a program that will record the purchases made at a store. For each purchase, read from the keyboard an it...
Java: An Introduction to Problem Solving and Programming (7th Edition)
When displaying a Java applet, the browser invokes the _____ to interpret the bytecode into the appropriate mac...
Web Development and Design Foundations with HTML5 (8th Edition)
Which category of C++ reference variables always produces aliases?
Concepts of Programming Languages (11th Edition)
Drives License Exam The local drivers license office has asked you to design a program that grades the written ...
Starting Out with Programming Logic and Design (4th Edition)
Write a loop that will write the word Hello to the screen ten times (when embedded in a complete program).
Problem Solving with C++ (9th Edition)
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, computer-science and related others by exploring similar questions and additional content below.Similar questions
- Create a Golf Game. Allow for two players. Prompt for the player names. Each player plays 18 holes. Use an array or List for each player to hold their number of swings for each hole. Logical methods should be implemented for different tasks (broken out below). It is up to you to determine the parameters and return types of each method as appropriate. Method 1 - For each hole, the player has a number of swings. Determine the player's swings by generating a random number between 1 and 4. Store each players number of swings in the array/list. Method 2 - After completing the 18 holes, add up the number of swings for each hole for each player. The player with the fewest number of swings is the winner. Method 3 - Save the game data into a CSV file in the main project (root) directory. Name the file "Golf_Game_Player1_Player2.csv" using the player's names. The information in the file should look like this: playername, scoreforhole1, scoreforhole2, scoreforhole3, etc... Method 4 - In the…arrow_forwardwriting multiple methods that work with arrays. These methods will perform specific functions and, in most cases, return results. Your class should be named Grades.arrow_forwardWrite a method that takes an animal name as a parameter and returns the largest count for that animal in a single Sighting record.arrow_forward
- In this assignment, you will need to add a new method to the Date class, which you can find on D2L in the "Sample Code" section. The new method should make a Date object's day, month, and year value change to the next day. In other words, add one day to the object's current date. Do not use any part of the built-in DateTime class, but you may want to use the DaysInMonth() method from the Date class. Examples: • If the Date object stores the date 12/31/2021, then after calling your method it should store the date 1/1/2022 • If the Date object stores the date 2/28/2022, then after calling your method it should store the date 3/1/2022 As noted in the common instructions, you only need to turn in your new method, not the entire Date class.arrow_forwardAdd the code to the end of your monitorLevels() method. It must become the last code of monitorLevels(). Study the comments and complete the code # Loop through displayList for i in range(0,len(displayList)): # Test if the first item in the current sub-list contains the text "Price Level" # Tip: Remember that each sub-list is a list within a list (displayList). So you have # to access its items via displayList followed by TWO indexes. . . . # Extract the second item from the current sub-list into a variable called priceLevel priceLevel = . . . # Test if priceLevel is between previousPrice and currentPrice OR # priceLevel == previousPrice OR # priceLevel == currentPrice if( . . . ): # Sound the alarm. Pass in the frequency and duration.…arrow_forwardWrite a method for the farmer class that allows a farmer object to pet all cows on the farm. Do not use arrays.arrow_forward
- Please help me create a cave class for a Hunt the Wumpus game. You can read the rules in it's entirety of the Hunt the Wumpus game online to get a better idea of the specifications. It's an actual game. INFORMATION: The object of this game is to find and kill the Wumpus within a minimum number of moves, before you get exhausted or run out of arrows. There is only one way to win: you must discover which room the Wumpus is hiding in and kill it by shooting an arrow into that room from an adjacent room. The Cave The Wumpus lives in a cave of 30 rooms. The rooms are hexagonal. Each room has up to 3 tunnels, allowing access to 1, 2 or 3 (out of 6) adjacent rooms. The attached diagram shows the layout of rooms in the cave. The map wraps around such that rooms on the edges (white cells) have neighbors from the opposite edge (blue cells). E.g., the neighbors of room 1 are rooms 25, 26, 2, 7, 6, and 30, and you could choose to connect room 1 to any of these rooms. Observe how room 1…arrow_forwardAdd another public method called add() to TestFraction1 class. This method adds another fraction to the ‘calling object’. Thus, the method will take a Fraction class object as a parameter, add this parameter fraction to the calling object (fraction), and return a Fraction object as a result. HINT: we can use cross multiplication to determine the numerator of the resultant Fraction. The denominator of the resultant Fraction is simply the multiplication of the denominators of the two other Fractions. import java.util.Scanner;//test programpublic class TestFraction1{public static void main(String[] args) {//create a Scanner objectScanner in = new Scanner(System.in);//create new fractionFraction frac = new Fraction();//declare numerator and denominatorint n=1,d;System.out.print("Enter Fraction's Numerator: ");//input numeratorn = in.nextInt();System.out.print("Enter Fraction's Denominator: ");//input denominatord = in.nextInt();//loop execute until the numerator is…arrow_forwardWrite a method belonging to the IntArrayBag class that searches for a target number. When found, return its index. If not found, return -1. Make sure to include the method header.arrow_forward
- The UnsortedTableMap class is located in the maps folder. In the attachment, you will find a partially implemented class called UnsortedMapOfLists, which extends UnsortedTableMap. The values associated with the keys in UnsortedMapOfLists are arrays. So you have an array with each key. Off course you can save an array in the value of UnsortedTableMap class without the class we are going to develop, but our class makes this easier, as it allows using a syntax like this: myMap["somekey", 1] to reach element at index 1 in the array associated with key "somekey". I already implemented methods __setitem__ and __getitem__. Your task is to: implement method __delitem__ . Deletion will be performed for an element in the array. If index is not given, delete the array associated with the key. implement a function (not a method in the class) to swap the arrays associated with two given keys. Add the required comment in method __getitem__. implement a main to verify that your code is working…arrow_forwardAdd methods to the STUDENT class that compare two STUDENT objects. One method should test for equality. The other methods should support the other possible comparisons. In each case, the method returns the result of the comparison of the two students' names. Place several STUDENT objects into a list and shuffle it. Then run the SORT method with this list and display all of the students' information.arrow_forwardCurrently, there are two draw rectangle methods in the DoodleController class. Since two different turtles need to draw a rectangle, create a draw rectangle method in the DoodleTurtle class that will take the width and height of the rectangle as parameters and draw a rectangle of the specified size. The size will be the number of steps by the turtle. With the new method introduced, the calls to drawRectangleWithLittleTurtle and drawRectangleWithBigTurtle can be replaced with a call to the turtle’s drawRectangle method passing in the desired size of the rectangle. Refactor the DoodleController accordingly. Note: When you are done with the refactoring the drawRectangleWithLittleTurtle and drawRectangleWithBigTurtle method in the DoodleController need to be deleted. After this refactoring, do not move on until you verify the program works as it did before.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 EducationStarting Out with Python (4th Edition)Computer ScienceISBN:9780134444321Author:Tony GaddisPublisher:PEARSONDigital Fundamentals (11th Edition)Computer ScienceISBN:9780132737968Author:Thomas L. FloydPublisher:PEARSON
- C How to Program (8th Edition)Computer ScienceISBN:9780133976892Author:Paul J. Deitel, Harvey DeitelPublisher:PEARSONDatabase Systems: Design, Implementation, & Manag...Computer ScienceISBN:9781337627900Author:Carlos Coronel, Steven MorrisPublisher:Cengage LearningProgrammable 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
Java Math Library; Author: Alex Lee;https://www.youtube.com/watch?v=ufegX5o8uc4;License: Standard YouTube License, CC-BY