Question 1

You have created a ShoppingCart class and a Fruit class. Which of the following will correctly declare an array list of Fruit objects in the ShoppingCart class?

Accepted Answer

A) public ShoppingCart { Private Fruit ArrayList fruits; } B) public ShoppingCart { Private ArrayList fruits; } C) public ShoppingCart { Private ArrayList fruits; } D) public ShoppingCart { Public ArrayList fruits; } A) public ShoppingCart { Private Fruit ArrayList fruits; } B) public ShoppingCart { Private ArrayList fruits; } C) public ShoppingCart { Private ArrayList fruits; } D) public ShoppingCart { Public ArrayList fruits; }

Question 2

Which of the following statements about a class is correct?

Accepted Answer

A)  A class should not have private instance variables. 
B)  Private instance variables are the interface to the class. 
C)  Private instance variables hide the implementation of a class from the class user. 
D)  Private instance variables should rarely be used in classes. 
A)  A class should not have private instance variables. 
B)  Private instance variables are the interface to the class. 
C)  Private instance variables hide the implementation of a class from the class user. 
D)  Private instance variables should rarely be used in classes.

Question 3

Consider the following code snippet:
Public class Vehicle
{
Private String model;
Private double rpm;
) . .
}
Which of the following methods would correctly remove the values of the class instance variables?

Accepted Answer

A)  public void reset()
{
Model = null;
Rpm = 0;
} 
B)  public void reset()
{
Model.clear();
Rpm = 0;
} 
C)  public void reset(String aModel, double theRpm)
{
Model = aModel;
Rpm = theRpm;
} 
D)  public void reset("",0)
{
} 
A)  public void reset()
{
Model = null;
Rpm = 0;
} 
B)  public void reset()
{
Model.clear();
Rpm = 0;
} 
C)  public void reset(String aModel, double theRpm)
{
Model = aModel;
Rpm = theRpm;
} 
D)  public void reset("",0)
{
}

Question 4

Which of the following declares a rpmRating instance variable for a Motor class that stores an integer value?

Accepted Answer

A)  private integer rpmRating; 
B)  private int rpmRating; 
C)  public integer rpmRating; 
D)  public int rpmRating; 
A)  private integer rpmRating; 
B)  private int rpmRating; 
C)  public integer rpmRating; 
D)  public int rpmRating;

Question 5

Which of the following is NOT part of the declaration of an instance variable?

Accepted Answer

A)  the return type 
B)  a modifier specifying the level of access 
C)  the data type 
D)  the name 
A)  the return type 
B)  a modifier specifying the level of access 
C)  the data type 
D)  the name

Question 6

Which of the following statements using data values in a class is NOT correct?

Accepted Answer

A)  You can use an instance variable's data value in an instance method. 
B)  You can use the argument of an instance method in that method. 
C)  You can use a global constant's value in an instance method. 
D)  You can use the argument of any instance method in any other method. 
A)  You can use an instance variable's data value in an instance method. 
B)  You can use the argument of an instance method in that method. 
C)  You can use a global constant's value in an instance method. 
D)  You can use the argument of any instance method in any other method.

Question 7

Insert the missing code in the following code fragment. This fragment is intended to initialize an instance variable.
Public class Employee
{
Private String empName;
) . .
Public Employee(String empName)
{
________
}
}

Accepted Answer

A)  Employee.empName = empName; 
B)  empName = this.empName; 
C)  this.empName = empName; 
D)  The constructor parameter variable cannot have the same name as an instance variable. 
A)  Employee.empName = empName; 
B)  empName = this.empName; 
C)  this.empName = empName; 
D)  The constructor parameter variable cannot have the same name as an instance variable.

Question 8

The object on which a method is invoked is called the ____.

Accepted Answer

A)  interface 
B)  procedure 
C)  implicit parameter 
D)  explicit parameter 
A)  interface 
B)  procedure 
C)  implicit parameter 
D)  explicit parameter

Question 9

Which of the following is a mutator method of the CashRegister class used in the textbook?

Accepted Answer

A)  getTotal 
B)  getCount 
C)  clear 
D)  The CashRegister class does not have any mutator methods. 
A)  getTotal 
B)  getCount 
C)  clear 
D)  The CashRegister class does not have any mutator methods.

Question 10

Private instance variables ___.

Accepted Answer

A)  can only be accessed by methods of a different class 
B)  can only be accessed by methods of the same class 
C)  cannot be accessed by methods of the same class 
D)  can only be accessed by the constructor of the class 
A)  can only be accessed by methods of a different class 
B)  can only be accessed by methods of the same class 
C)  cannot be accessed by methods of the same class 
D)  can only be accessed by the constructor of the class

Question 11

Consider the following code snippet:
Public class Student
{
Private static int lastAssignedStudentNum = 1500;
{ ) . . }
}
Which of the following statements about this code is correct?

Accepted Answer

A)  Each object created from this class will have its own lastAssignedStudentNum variable. 
B)  All objects created from this class will share the lastAssignedStudentNum variable. 
C)  The lastAssignedStudentNum variable's value cannot be changed. 
D)  You cannot assign a value to a static variable. 
A)  Each object created from this class will have its own lastAssignedStudentNum variable. 
B)  All objects created from this class will share the lastAssignedStudentNum variable. 
C)  The lastAssignedStudentNum variable's value cannot be changed. 
D)  You cannot assign a value to a static variable.

Question 12

You have created a Coin class and a Purse class. Which of the following will correctly allow the Purse class to collect Coin objects?

Accepted Answer

A) public Purse { Private Coin ArrayList coins; } B) public Purse { Private ArrayList coins; } C) public Purse { Private ArrayList coins; } D) public Purse { Public ArrayList coins; } A) public Purse { Private Coin ArrayList coins; } B) public Purse { Private ArrayList coins; } C) public Purse { Private ArrayList coins; } D) public Purse { Public ArrayList coins; }

Question 13

Which of the following are considered members of a class?

Accepted Answer

A)  Private instance variables and methods. 
B)  All instance variables and methods. 
C)  Non-static instance variables and methods. 
D)  Public instance variables and methods. 
A)  Private instance variables and methods. 
B)  All instance variables and methods. 
C)  Non-static instance variables and methods. 
D)  Public instance variables and methods.

Question 14

Consider the following code snippet:
Public class Vessel
{
Private String type;
Public String Vessel(String type)
{
) . .
}
}
What is wrong with this code?

Accepted Answer

A)  The class instance variable type must be initialized when it is declared. 
B)  The constructor must not have any arguments. 
C)  The constructor must not have a return type declared. 
D)  The constructor's return type must be void. 
A)  The class instance variable type must be initialized when it is declared. 
B)  The constructor must not have any arguments. 
C)  The constructor must not have a return type declared. 
D)  The constructor's return type must be void.

Question 15

Which of the following is an accessor method of the CashRegister class used in the textbook?

Accepted Answer

A)  getTotal 
B)  addItem 
C)  clear 
D)  The CashRegister class does not have any accessor methods. 
A)  getTotal 
B)  addItem 
C)  clear 
D)  The CashRegister class does not have any accessor methods.

Question 16

Consider the following code snippet:
Public class Employee
{
Private String empName;
Public String getEmpName()
{ ) . . }
}
Which of the following statements is correct?

Accepted Answer

A)  The getEmpName method can be accessed by any user of an Employee object. 
B)  The getEmpName method can be accessed only by methods of the Employee class. 
C)  The getEmpName method can be accessed only by methods of another class. 
D)  The getEmpName method cannot be accessed at all. 
A)  The getEmpName method can be accessed by any user of an Employee object. 
B)  The getEmpName method can be accessed only by methods of the Employee class. 
C)  The getEmpName method can be accessed only by methods of another class. 
D)  The getEmpName method cannot be accessed at all.

Question 17

Consider the following code snippet:
Public class AutoRace
{
Private int lapCount;
Private double totalTime;
) . .
}
Which of the following completeLap methods would correctly track how many laps occurred?

Accepted Answer

A)  public void completeLap(double lapTime)
{
TotalTime = totalTime + lapTime;
} 
B)  public void completeLap(double lapTime)
{
TotalTime = totalTime + lapTime;
LapCount ++;
} 
C)  public void completeLap(double lapTime)
{
TotalTime = totalTime + lapTime;
LapCount = lapCount + lapTime;
} 
D)  public void completeLap(double lapTime)
{
TotalTime = lapCount + lapTime;
} 
A)  public void completeLap(double lapTime)
{
TotalTime = totalTime + lapTime;
} 
B)  public void completeLap(double lapTime)
{
TotalTime = totalTime + lapTime;
LapCount ++;
} 
C)  public void completeLap(double lapTime)
{
TotalTime = totalTime + lapTime;
LapCount = lapCount + lapTime;
} 
D)  public void completeLap(double lapTime)
{
TotalTime = lapCount + lapTime;
}

Question 18

You are creating a class named Vessel. Which statement correctly declares a constructor for this class?

Accepted Answer

A)  public Vessel() 
B)  public void Vessel() 
C)  void Vessel() 
D)  new Vessel() 
A)  public Vessel() 
B)  public void Vessel() 
C)  void Vessel() 
D)  new Vessel()

Question 19

Which of the following statements about encapsulation is correct?

Accepted Answer

A)  Encapsulation enables changes to the public interface without affecting users of the class. 
B)  Encapsulation prohibits changes to the implementation details to ensure that users of the class will not be affected. 
C)  Encapsulation enables changes to the implementation details without affecting users of the class. 
D)  Encapsulation provides an easier means of transporting class information. 
A)  Encapsulation enables changes to the public interface without affecting users of the class. 
B)  Encapsulation prohibits changes to the implementation details to ensure that users of the class will not be affected. 
C)  Encapsulation enables changes to the implementation details without affecting users of the class. 
D)  Encapsulation provides an easier means of transporting class information.

Question 20

Each object of a class has a separate copy of each ___.

Accepted Answer

A)  method 
B)  instance variable 
C)  constructor 
D)  class 
A)  method 
B)  instance variable 
C)  constructor 
D)  class

Exam 8: Objects and Classes

You have created a ShoppingCart class and a Fruit class. Which of the following will correctly declare an array list of Fruit objects in the ShoppingCart class?

Which of the following statements about a class is correct?

Consider the following code snippet: Public class Vehicle { Private String model; Private double rpm; ) . . } Which of the following methods would correctly remove the values of the class instance variables?

Which of the following declares a rpmRating instance variable for a Motor class that stores an integer value?

Which of the following is NOT part of the declaration of an instance variable?

Which of the following statements using data values in a class is NOT correct?

Insert the missing code in the following code fragment. This fragment is intended to initialize an instance variable. Public class Employee { Private String empName; ) . . Public Employee(String empName) { ________ } }

The object on which a method is invoked is called the ____.

Which of the following is a mutator method of the CashRegister class used in the textbook?

Private instance variables ___.

Consider the following code snippet: Public class Student { Private static int lastAssignedStudentNum = 1500; { ) . . } } Which of the following statements about this code is correct?

You have created a Coin class and a Purse class. Which of the following will correctly allow the Purse class to collect Coin objects?

Which of the following are considered members of a class?

Consider the following code snippet: Public class Vessel { Private String type; Public String Vessel(String type) { ) . . } } What is wrong with this code?

Which of the following is an accessor method of the CashRegister class used in the textbook?

Consider the following code snippet: Public class Employee { Private String empName; Public String getEmpName() { ) . . } } Which of the following statements is correct?

Consider the following code snippet: Public class AutoRace { Private int lapCount; Private double totalTime; ) . . } Which of the following completeLap methods would correctly track how many laps occurred?

You are creating a class named Vessel. Which statement correctly declares a constructor for this class?

Which of the following statements about encapsulation is correct?

Each object of a class has a separate copy of each ___.

Introduction

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