Java: An Introduction to Problem Solving and Programming (7th Edition)
7th Edition
ISBN: 9780133766264
Author: Walter Savitch
Publisher: PEARSON
expand_more
expand_more
format_list_bulleted
Concept explainers
Videos
Textbook Question
Chapter 9, Problem 10E
Suppose that you are going to create an object used to count the number of people in a room. We know that the number of people in the room can never be negative. Create a RoomCounter class having three public methods:
- addPerson—adds one person to the room
- removePerson—removes one person from the room
- getCount—returns the number of people in the room
If removePerson would make the number of people less than zero, throw a NegativeCounterException.
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
Write a compareTo method that compares two Song objects based on the artist, and title within artist. For example, given the following Songobjects:
"Glass Animals""Heat Waves"
"Elton John, Dua Lipa""Cold Heart"
"Adele""Easy on Me"
"Doja Cat""Kiss Me More"
"Adele""My Little Love"
They will be put in the following order:
"Adele""Easy on Me"
"Adele""My Little Love"
"Doja Cat""Kiss Me More"
"Elton John, Dua Lipa""Cold Heart"
"Glass Animals""Heat Waves"
In which class does the compareTo method belong?
I am creating a digital clock and I am trying to make sure that it does not allow an hour less than zero. All of my others paramters are being met (the clock is being created at hour zero and is creating at hour 23) however, I can't figure out why it is allowing hours that are less than zero. This is my code: public class DigitalClock { private int currentHour; private int currentMinutes; public int getHour() { return currentHour; } public void setHour(int currentHour) { this.currentHour = currentHour; } public int getMinutes() { return currentMinutes; } public void setMinutes(int currentMinutes) { this.currentMinutes = currentMinutes; } public DigitalClock (int hour, int minutes) { if (hour <= 0 && hour <= 23) currentHour = hour; else currentHour = 0; if (0 <= minutes && minutes <=59) currentMinutes = minutes; else…
Suppose that a Scanner object contains a bunch of tokens all on a single line separated by spaces. For example:
100.5 30.4 pizza 56.8 1000.3 8.2
Also suppose that you have a particular item that you know the price of. Let’s use the following example:
Kindle: 99.99
Write a static method: public static double priceIsRight(Scanner s, double price) that takes a Scanner and an item price as parameters and returns the bid that is closest to the item price but not greater than the item price. If all bids are greater than the price, return 0.0. If there are no bids (Scanner is empty) return 0.0. You can assume the Scanner is not null.
In the above example. 56.8 should be returned, since it is the number that is closest to 99.99 but not over 99.99.
Notice that there may be some invalid tokens in the Scanner's input. The above example has pizza as one of its tokens, which is clearly not a valid bid. Your method should throw these tokens away and not consider them as bids.
It is probably…
Chapter 9 Solutions
Java: An Introduction to Problem Solving and Programming (7th Edition)
Ch. 9.1 - Prob. 1STQCh. 9.1 - What output would the code in the previous...Ch. 9.1 - Prob. 3STQCh. 9.1 - Prob. 4STQCh. 9.1 - Prob. 5STQCh. 9.1 - Prob. 6STQCh. 9.1 - Prob. 7STQCh. 9.1 - Prob. 8STQCh. 9.1 - In the code given in Self-Test Question 1,...Ch. 9.1 - In the code given in Self-Test Question 1,...
Ch. 9.1 - Prob. 11STQCh. 9.1 - Prob. 12STQCh. 9.1 - Prob. 13STQCh. 9.1 - Prob. 14STQCh. 9.2 - Prob. 15STQCh. 9.2 - Prob. 16STQCh. 9.2 - Prob. 17STQCh. 9.2 - Prob. 18STQCh. 9.2 - Prob. 19STQCh. 9.2 - Prob. 20STQCh. 9.2 - Suppose that, in Self-Test Question 19, we change...Ch. 9.2 - Prob. 22STQCh. 9.2 - Prob. 23STQCh. 9.3 - Prob. 24STQCh. 9.3 - Prob. 25STQCh. 9.3 - Prob. 26STQCh. 9.3 - Prob. 27STQCh. 9.3 - Prob. 28STQCh. 9.3 - Repeat Self-Test Question 27, but change the value...Ch. 9.3 - Prob. 30STQCh. 9.3 - Prob. 31STQCh. 9.3 - Prob. 32STQCh. 9.3 - Consider the following program: a. What output...Ch. 9.3 - Write an accessor method called getPrecision that...Ch. 9.3 - Prob. 35STQCh. 9.4 - Rewrite the class ColorDemo in Listing 9.13 so...Ch. 9.4 - Prob. 37STQCh. 9 - Write a program that allows students to schedule...Ch. 9 - Prob. 2ECh. 9 - Prob. 3ECh. 9 - Prob. 4ECh. 9 - Prob. 5ECh. 9 - Write code that reads a string from the keyboard...Ch. 9 - Create a class Rational that represents a rational...Ch. 9 - Prob. 9ECh. 9 - Suppose that you are going to create an object...Ch. 9 - Revise the class RoomCounter described in the...Ch. 9 - Prob. 12ECh. 9 - Write a class LapTimer that can be used to time...Ch. 9 - Prob. 1PCh. 9 - Prob. 2PCh. 9 - Prob. 3PCh. 9 - Write a program that uses the class calculator in...Ch. 9 - Prob. 3PPCh. 9 - Prob. 7PPCh. 9 - Prob. 9PPCh. 9 - Suppose that you are in change of customer service...Ch. 9 - Write an application that implements a trip-time...
Additional Engineering Textbook Solutions
Find more solutions based on key concepts
The ________ object is assumed to exist and it is not necessary to include it as an object when referring to it...
Web Development and Design Foundations with HTML5 (9th Edition) (What's New in Computer Science)
What is the output of the following program? #include iostream using namespace std; void fund(double, int); // ...
Starting Out with C++ from Control Structures to Objects (9th Edition)
Indicate true or false for the following statements: a.A protected datum or method can be accessed by any class...
Introduction to Java Programming and Data Structures, Comprehensive Version (11th Edition)
Use the following tables for your answers to questions 3.7 through 3.51 : PET_OWNER (OwnerID, OwnerLasst Name, ...
Database Concepts (8th Edition)
What does a bounding box indicate about an object in the Designer?
Starting Out With Visual Basic (8th Edition)
The ________ object is assumed to exist and it is not necessary to include it as an object when referring to it...
Web Development and Design Foundations with HTML5 (8th 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
- Suppose that a Scanner object contains a bunch of tokens all on a single line separated by spaces. For example: 100.5 30.4 pizza 56.8 1000.3 8.2 Also suppose that you have a particular item that you know the price of. Let’s use the following example: Kindle: 99.99 Write a static method: public static double priceIsRight(Scanner s, double price) that takes a Scanner and an item price as parameters and returns the bid that is closest to the item price but not greater than the item price. If all bids are greater than the price, return 0.0. If there are no bids (Scanner is empty) return 0.0. You can assume the Scanner is not null. In the above example. 56.8 should be returned, since it is the number that is closest to 99.99 but not over 99.99. Notice that there may be some invalid tokens in the Scanner's input. The above example has pizza as one of its tokens, which is clearly not a valid bid. Your method should throw these tokens away and not consider them as bids. It is probably…arrow_forwardMake a class called MyCircle, which models a circle.The class contains: • One private instance variables: radius (int). • A constructor that constructs a circle with the given radius. • Write getter to get radius of the circle. • Write setter to set the radius of the circle. • A getArea() method that returns the area of the circle in float. Area of Circle = pr2 (p represent pi value) • A getCircumference() method that returns the circumference of the circle. Circumference of Circle= 2pr (p represent pi value) Create main class that construct two circles, assign radius to both circles and display their respective area and circumference.arrow_forwardWrite a program that displays heads (H) or tails (T) for each of ninecoins, as shown in Figure 12.31c–d. When a cell is clicked, the coin is flipped.Write a custom cell class that extends Label. In the initializer of the class, bindthe event <Button-1> with the method for flipping the coin. When the program starts, all cells initially display H.arrow_forward
- i need it in util.java.scanner form and can you make it so i can copy and past it please thanks A regular triangle is one for which all sides are congruent and all interior angles. Create a class RegularTriangle with a field side (int) Create a constructor which accepts an int parameter and will assign the parameter to field side Create assessor and mutator for this class Create a method getPerimeter() which should return 3*side;arrow_forwardImplement a class Car with the following properties. A car has a certain fuel efficiency(measured in miles/gallon or liters/km—pick one) and a certain amount of fuel in the gastank. The efficiency is specified in the constructor, and the initial fuel level is 0.Supply a method drive that simulates driving the car for a certain distance, reducing theamount of gasoline in the fuel tank. Also supply methods getGasInTank, returning thecurrent amount of gasoline in the fuel tank, and addGas, to add gasoline to the fuel tank.Sample usage:Car myHybrid = new Car(50); // 50 miles per gallonmyHybrid.addGas(20); // Tank 20 gallonsmyHybrid.drive(100); // Drive 100 milesdouble gasLeft = myHybrid.getGasInTank(); // Get gas remaining in tankYou may assume that the drive method is never called with a distance that consumes morethan the available gas. Supply a CarTester class that tests all methods.arrow_forward*Create a rectangle class using all methods given below.* *Use Java* Class Rectangle will have the following instance variables: •x –a double that represents the x coordinate of the lower left vertex of the rectangle •y –a double that represents the y coordinate of the lower left vertex of the rectangle •width –a double that represents the width of the rectangle •height–a double that represents the height of the rectangle •color –a String that represents the color of the rectangle •filled –a boolean variable that is true if the rectangle is filled, and false if it is not Rectangle constructor: The constructor should be: Rectangle (double x, double y, double height, double width, String color, boolean filled) Parameters are, in order,the x and y coordinates of the lower left corner, the height, the width, and the color of the rectangle. The constructor should check that these values represent a valid rectangle. If they do, then it should initialize the rectangle to these values.…arrow_forward
- Implement a class Moth that models a moth flying along a straight line. The moth hasa position, which is the distance from a fixed origin. When the moth moves toward apoint of light, its new position is halfway between its old position and the position ofthe light source. Find the instance variable(s), define and implement the constructor(s), then supplythe following methods:- public void moveToLight(double lightPosition)- public double getPosition() Document your class, generate Javadoc documentation and produce a test program ‘MothTester’that construct a moth, move it toward a couple of light sources, and check that the moth’s positionis as expected. Add a comment to your class Moth that explains how you can make the Moth immobile after 10moves.arrow_forwardPLEASE ENSURE TO USE THE FRAMEWORK PROVIDED IN THE IMAGES, AND THAT IT WORKS WITH THE TESTER CLASS. PLEASE DONT EDIT THE TEST CLASS. Simulate a circuit for controlling a hallway light that has switches at both ends of the hallway. Each switch can be up or down, and the light can be on or off. Toggling either switch turns the lamp on or off. Provide methods public int getFirstSwitchState() // 0 for down, 1 for up public int getSecondSwitchState()public int getLampState() // 0 for off, 1 for onpublic void toggleFirstSwitch() public void toggleSecondSwitch()arrow_forwardWrite a class RangeInput that allows users to enter a value within a range of values that is provided in the constructor. An example would be a temperature control switch in a car that allows inputs between 60 and 80 degrees Fahrenheit. The input control has “up” and “down” buttons. Provide up and down methods to change the current value. The initial value is the midpoint between the limits. As with the preceding exercises, use Math.min and Math.max to limit the value. Write a sample program that simulates clicks on controls for the passenger and driver seats. PLEASE USE THE TEMPLATES PROVIDED AND ENSURE THAT IT WORKS WITH THE TEST CLASSarrow_forward
- Write a class RangeInput that allows users to enter a value within a range of values that is provided in the constructor. An example would be a temperature control switch in a car that allows inputs between 60 and 80 degrees Fahrenheit. The input control has “up” and “down” buttons. Provide up and down methods to change the current value. The initial value is the midpoint between the limits. As with the preceding exercises, use Math.min and Math.max to limit the value. Write a sample program that simulates clicks on controls for the passenger and driver seats. Please ensure that it works with the test class provided.arrow_forwardGiving the following code class Rectangle: def init (self, I, w): self.length = / self width = w def rectangle area(self): return self.length*self width def rectangle _perimeter(self): return (self.length+self.width)*2 RI = Rectangle(20, 12) print(Rl .rectangle_area()) print(Rl .rectangle_perimeter()) Answer the questions How many classes we have on the above example? What is the role of the method init (.)? How many methods are defined? How many objects are created? How we invoke any method. Cite an example from the above code? Instanciate 2 rectangles using your Rectangle class, and draw schema representing the namespacesarrow_forwardcan you please help me with the last part of this code because I don't understand this; part of the code is below and the other part of the code is in the photo. question: In the LightsOutPuzzle class, write a method copy(self) that returns a new LightsOutPuzzle object initialized with a deep copy of the current board. Changes made to the original puzzle should not be reflected in the copy, and vice versa. >>> p = create_puzzle(3, 3)>>> p2 = p.copy()>>> p.get_board() == p2.get_board()True >>> p = create_puzzle(3, 3)>>> p2 = p.copy()>>> p.perform_move(1, 1)>>> p.get_board() == p2.get_board()False In the LightsOutPuzzle class, write a method successors(self) that yields all successors of the puzzle as (move, new-puzzle) tuples, where moves themselves are (row, column) tuples. The second element of each successor should be a new LightsOutPuzzle object whose board is the result of applying the corresponding move to the current…arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
EBK JAVA PROGRAMMINGComputer ScienceISBN:9781337671385Author:FARRELLPublisher:CENGAGE LEARNING - CONSIGNMENT
EBK JAVA PROGRAMMING
Computer Science
ISBN:9781337671385
Author:FARRELL
Publisher:CENGAGE LEARNING - CONSIGNMENT
Java Math Library; Author: Alex Lee;https://www.youtube.com/watch?v=ufegX5o8uc4;License: Standard YouTube License, CC-BY