AP Computer Science AScoring GuideUnit 5 Review1.Consider the following class definition.public class Element{public static int max_value = 0;private int value;public Element (int v){value = v;if (value > max_value){max_value = value;}}}The following code segment appears in a class other thanElement.for (int i = 0; i < 5; i++){int k = (int) (Math.random() * 10 + 1);if (k >= Element.max_value){Element e = new Element(k);}}Which of the following best describes the behavior of the code segment?AExactly 5Elementobjects are created.Exactly 10Elementobjects are created.Between 0 and 5Elementobjects are created, andElement.max_valueis increased only for thefirst object created.Between 1 and 5Elementobjects are created, andElement.max_valueis increased for everyobject created.Between 1 and 5Elementobjects are created, andElement.max_valueis increased for at least oneobject created.BCDE Copyright © 2021. The College Board. These materials are part of a College Board program. Use or distribution of these materials online or in printbeyond your school’s participation in the program is prohibited.Page 1 of 26 Related Textbook Solutions See moreAP Computer Science AScoring GuideUnit 5 Review2.Consider the following class definition.public class WordClass{private final String word;private static String max_word = "";public WordClass (String s){word = s;if (word.length() > max_word.length()){max_word = word;}}}Which of the following is a true statement about the behavior ofWordClassobjects?BCD.E Get answer to your question and much more Copyright © 2021. The College Board. These materials are part of a College Board program. Use or distribution of these materials online or in printbeyond your school’s participation in the program is prohibited.Page 2 of 263.A car dealership needs a program to store information about the cars for sale. For each car, they want tokeep track of the following information: number of doors (2 or 4), whether the car has air conditioning, andits average number of miles per gallon. Which of the following is the best object-oriented program design? AP Computer Science AScoring GuideUnit 5 ReviewCopyright © 2021. The College Board. These materials are part of a College Board program. Use or distribution of these materials online or in printbeyond your school’s participation in the program is prohibited.Page 3 of 26AUse one class, Car, with three instance variables:int numDoors, boolean hasAir, anddouble milesPerGallon. Upload your study docs or become a Course Hero member to access this document Upload your study docs or become a Course Hero member to access this document End of preview. Want to read all 26 pages? Upload your study docs or become a Course Hero member to access this document Tags Object Oriented Programming, Subroutine
6-12-1: The Liquid class will contain two double attributes for a liquid’s boiling point temperature and freezing point temperature. The class will also contain a constructor. public class Liquid
{
/* missing code */
}
Which of the following replacements for /* missing code */ is the most appropriate
implementation of the class?
private double boilingPoint; private double freezingPoint; public Liquid(double boilingPoint, double freezingPoint) { /* implementation not shown */ } Correct! The instance variables should be private and the constructor and methods should be public. private double boilingPoint; private double freezingPoint; private Liquid(double boilingPoint, double freezingPoint) { /* implementation not shown */ } Constructors should be public. private double boilingPoint; public double freezingPoint; private Liquid(double freezingPoint, double boilingPoint) { /* implementation not shown */ } The instance variables should be private and the constructor and methods should be public. public double boilingPoint; public double freezingPoint; private Liquid(double boilingPoint, double freezingPoint) { /* implementation not shown */ } The instance variables should be private and the constructor and methods should be public. public double freezingPoint; public double boilingPoint; public Liquid(double freezingPoint, double boilingPoint) { /* implementation not shown */ } The instance variables should be private.
6-12-2: The Cat class below will contain two String attributes and one int attribute for name, color, and age; a constructor; and an adoptCat method. The adoptCat method is intended to be accessed outside the class. public class Cat { /* missing code */ } Which of the following replacements for /* missing code */ is the most appropriate implementation of the class?
6-12-3: Consider the definition of the Party class below. The class uses the instance variable numOfPeople to indicate how many people are at the party. public class Party { private int numOfPeople; private String partyHost; public Party (String name, int people) { partyHost = name; numOfPeople = people; } } Which of the following statements will create a Party object that represents a party that has three people at it?
6-12-4: Consider the following class definition. Each object of the class Party will store the party host’s name as partyHost, the number of people as numOfPeople, and the capacity that the event can hold as capacity. Which of the following code segments, found in a class other than Party, can be used to create a party hosted by Charlie without anyone there initially, but the place can hold 78 people ? public class Party { private String partyHost; private int numOfPeople; private int capacity; public Party(String name, int num, int cap) { partyHost = name; numOfPeople = num; capacity = cap; } public Party (String name, int cap) { partyHost = name; numOfPeople = 0; capacity = cap; } /* Other methods not shown */ } I. Party b = new Party("Charlie", 78); II. Party b = new Party("Charlie", 0, 70+8); III. Party b = new Party("Charlie", 0, 78);
6-12-5: Consider the following class definition. public class Party { private int numOfPeople; private double volumeOfMusic; /* missing constructor */ } The following statement appears in a method in a class other than Party. It is intended to create a new Party object p with its attributes set to 10 and 5.0. Party p = new Party(10, 5.0); Which of the following can be used to replace /* missing constructor */ so that the object p is correctly created?
6-12-6: Consider the following class definition that defines a Liquid class with a boilingPoint, a currentTemperature, and a freezingPoint. For example, Liquid water = new Liquid(100, 50, 0); defines a water object with a boiling point of 100, a current temperature of 50, and a freezing temperature of 0. public class Liquid { private int boilingPoint; private int currentTemp; private int freezingPoint; public Liquid(int bp, int ct, int fp) { boilingPoint = bp; currentTemp = ct; freezingPoint = fp; } /* Other methods not shown */ } Which of the following preconditions is reasonable for the Liquid constructor?
6-12-7: Consider the following Cat class, with the cat’s age stored in the method’s int attribute. The getAge method is intended to allow methods in other classes to access a Cat object’s age value; however, it does not work as intended. Which of the following best explains why the getAge method does NOT work as intended?
6-12-8: Consider the following Liquid class. The currentTemperature is stored in the method’s int attribute. The getCurrentTemp method is intended to allow methods in other classes to access a Liquid object’s currentTemperature value; however, it does not work as intended. Which of the following best explains why the getCurrentTemperature method does NOT work as intended? public class Liquid { private int currentTemperature; public Liquid(int ct) { currentTemperature = ct; } public void getCurrentTemperature() { return currentTemperature; } }
6-12-9: Consider the following class definition. public class Liquid { private int currentTemp; public Liquid(int temp) { currentTemp = temp; } public int getTemp() { return currentTemp; } public void resetTemp(int new_temp) { currentTemp = new_temp; } } Consider the following code segment, which appears in a method in a class other than Liquid. The code segment does not compile. Liquid liq = new Liquid(50); System.out.println("The temperature of the liquid is " + liq.currentTemp); Which of the following best identifies the reason the code segment does not compile?
6-12-10: In the Liquid class below, the raiseTemperature method is intended to increase the value of the instance variable currentTemp by the value of the parameter increase. The method does not work as intended. public class Liquid { private int currentTemp; public Liquid(int ct) { currentTemp = ct; } public void raiseTemperature(int increase) // Line 10 { return currentTemp + increase; // Line 12 } } Which of the following changes should be made so that the class definition compiles without error and the method raiseTemperature works as intended?
6-12-11: Consider the following class definition. The calculatePizzaCostPerPerson method is intended to calculate the amount each person at the party must pay for pizza. The amount is equal to the total price of all the pizza boxes divided by the number of people at the party. Which of the following code segments should replace missing code so that the calculatePizzaCostPerPerson method will work as intended? public class Party { private int numOfPeople; //number of people at the party public Party(int people) { numOfPeople = people; } public double calculatePizzaCostPerPerson(int numOfBoxes, double priceOfOnePizzaBox) { /* missing code */ } }
6-12-12: Consider the Party class below. public class Party { private int numOfPeople; //number of people at the party private int capacity; //total capacity of people at party public Party(int people, int cap) { numOfPeople = people; capacity = cap; } public boolean updateNumOfPeople(int additionalPeople) { /* missing code */ } } The class contains the updateNumOfPeople method, which is intended to update the instance variable numOfPeople under certain conditions and return a value indicating whether the update was successful. If adding additionalPeople to the current number of people would lead to the number going over the capacity, then the update would be unsuccessful. Otherwise, if adding the number of additional people is still below or at the capacity, the update is successful. Which of the following code segments can replace missing code to ensure that the updateNumOfPeople method works as intended? I. if (numOfPeople + additionalPeople > capacity) { return false; } else { numOfPeople += additionalPeople; return true; } II. if (numOfPeople + additionalPeople <= capacity) { numOfPeople += additionalPeople; return true; } else { return false; } III. if (numOfPeople += additionalPeople <= capacity) { return true; } else { return false; }
6-12-13: Consider the following class definition. public class Liquid { private int currentTemp; private int boilingPoint; public Liquid(int ct, int bp) { currentTemp = ct; boilingPoint = bp; } public void changeTemp(int newTemp) { currentTemp = newTemp; } public void increaseTemp(int howMuch) { currentTemp = newTemp + howMuch; } } Which of the following best explains why the class will not compile?
6-12-14: Consider the following class definition for Party. The following code segment appears in a method in a class other than Party. The code segment is intended to print the value 30, but does not print the correct value because of an error in the Party class. Which of the following best explains why the correct value isn’t printed? Party p = new Party(20, 15); p.orderMoreFood(20); p.eatFood(5); System.out.println(p.getBoxesOfFood()); public class Party { private int boxesOfFood; private int numOfPeople; public Party(int people, int foodBoxes) { numOfPeople = people; boxesOfFood = foodBoxes; } public void orderMoreFood(int additionalFoodBoxes) { int updatedAmountOfFood = boxesOfFood + additionalFoodBoxes; boxesOfFood = updatedAmountOfFood; } public int getNumOfPeople() { return numOfPeople; } public int getBoxesOfFood() { return boxesOfFood; } public void eatFood(int eatenBoxes) { boxesOfFood = updatedAmountOfFood - eatenBoxes; } }
6-12-15: Consider the following class definitions. public class Party { private String partyHost; private int monthOfParty; private int partyStartTime; public Party (String h, int month, int startTime) { partyHost = h; monthOfParty = month; partyStartTime = startTime; } public int getMonth() { return monthOfParty; } public int getStartTime() { return partyStartTime; } public String getHost() { return partyHost; } public void addToOptions(PartyOptions o) { o.addParty(this); } } public class PartyOptions { private int onlyThisMonth; public PartyOptions(int month) { onlyThisMonth = month; } /* A Party should only be added to this PartyOption if the party’s month matches onlyThisMonth */ public void addParty(Party p) { if (p.getMonth() == onlyThisMonth) { System.out.print("Party by " + p.getHost() + " accepted; "); } else { System.out.print("Party by " + p.getHost() + " rejected; "); } } } Consider the following code segment, which appears in a class other than Party or PartyOptions. Party p1 = new Party("Kerry", 10, 7); Party p2 = new Party("Jules", 9, 6); PartyOptions options = new PartyOptions(10); p1.addToOptions(options); p2.addToOptions(options); |