Question 1

The ____ operator is used to construct an object from a class.

Accepted Answer

A)  add 
B)  create 
C)  new 
D)  construct 
A)  add 
B)  create 
C)  new 
D)  construct

Question 2

Insert the missing code in the following code fragment. This fragment is intended to implement a method to set the value stored in an instance variable.
Public class Employee
{
Private String empID;
Private boolean hourly;
) . .
_______
{
Hourly = isHourly;
}
}

Accepted Answer

A)  public void setHourly(String isHourly) 
B)  public void getHourly() 
C)  public boolean getHourly() 
D)  public boolean setHourly(boolean isHourly) 
A)  public void setHourly(String isHourly) 
B)  public void getHourly() 
C)  public boolean getHourly() 
D)  public boolean setHourly(boolean isHourly)

Question 3

Given the following class definition, which of the following are NOT considered part of the class's public interface?
Public class CashRegister
{
Public static final double DIME_VALUE = 0.1;
Private static int objectCounter;
Public void updateDimes(int dimes) {…}
Private boolean updateCounter(int counter) {…}
}

Accepted Answer

A)  objectCounter and updateCounter 
B)  DIME_VALUE and objectCounter 
C)  DIME_VALUE and updateDimes 
D)  updateDimes and updateCounter 
A)  objectCounter and updateCounter 
B)  DIME_VALUE and objectCounter 
C)  DIME_VALUE and updateDimes 
D)  updateDimes and updateCounter

Question 4

Which of the following statements about instance methods is correct?

Accepted Answer

A)  An instance method should always be declared as public. 
B)  An instance method should always be declared as private. 
C)  An instance method should be declared as public only if it is a helper method. 
D)  An instance method should be declared as private only if it is a helper method. 
A)  An instance method should always be declared as public. 
B)  An instance method should always be declared as private. 
C)  An instance method should be declared as public only if it is a helper method. 
D)  An instance method should be declared as private only if it is a helper method.

Question 5

Consider the following code snippet:
Public class Vehicle
{
) . .
Public void setVehicleAttributes(String attributes)
{) . . }
Public String getVehicleAtrributes()
{) . . }
Public String getModelName()
{) . . }
}
Assuming that the names of the methods reflect their action, which of the following statements about these instance methods is NOT correct?

Accepted Answer

A)  setVehicleAttributes is an accessor method. 
B)  setVehicleAttributes is a mutator method. 
C)  getVehicleAttributes is an accessor method. 
D)  getModelName is an accessor method. 
A)  setVehicleAttributes is an accessor method. 
B)  setVehicleAttributes is a mutator method. 
C)  getVehicleAttributes is an accessor method. 
D)  getModelName is an accessor method.

Question 6

Consider the following code snippet:
Coin coin1 = new Coin("dime", 0.10);
Coin coin2 = coin1;
Which of the following statements is NOT correct?

Accepted Answer

A)  coin1 and coin2 are object references. 
B)  coin1 and coin2 refer to the same object. 
C)  coin1 and coin2 contain the same memory location. 
D)  coin1 and coin2 each have their own set of instance variables. 
A)  coin1 and coin2 are object references. 
B)  coin1 and coin2 refer to the same object. 
C)  coin1 and coin2 contain the same memory location. 
D)  coin1 and coin2 each have their own set of instance variables.

Question 7

The process of hiding object data and providing methods for data access is called ____.

Accepted Answer

A)  documentation 
B)  encapsulation 
C)  implementation 
D)  initialization 
A)  documentation 
B)  encapsulation 
C)  implementation 
D)  initialization

Question 8

Consider the following code snippet:
Public int getCoinValue(String coinName)
{ ) . . }
Which of the following statements is correct?

Accepted Answer

A)  coinName is an implicit parameter. 
B)  coinName is an explicit parameter. 
C)  coinName is the object on which this method is invoked. 
D)  coinName is an instance variable. 
A)  coinName is an implicit parameter. 
B)  coinName is an explicit parameter. 
C)  coinName is the object on which this method is invoked. 
D)  coinName is an instance variable.

Question 9

Given the following class definition, which of the following are considered part of the class's public interface?
Public class Motorcycle
{
Public static final int WHEEL_COUNT = 2;
Private int rpmRating;
Public void updatePrice(double increase) {…}
Private String designCode() {…}
}

Accepted Answer

A)  rpmRating and designCode 
B)  WHEEL_COUNT and designCode 
C)  WHEEL_COUNT and updatePrice 
D)  updatePrice and designCode 
A)  rpmRating and designCode 
B)  WHEEL_COUNT and designCode 
C)  WHEEL_COUNT and updatePrice 
D)  updatePrice and designCode

Question 10

Which of the following statements about classes is correct?

Accepted Answer

A)  A class is an object that can be manipulated by a program. 
B)  A class describes a set of objects with the same behavior. 
C)  Class is another name for a method. 
D)  A class can contain only methods. 
A)  A class is an object that can be manipulated by a program. 
B)  A class describes a set of objects with the same behavior. 
C)  Class is another name for a method. 
D)  A class can contain only methods.

Question 11

Which statement about instance variables is correct?

Accepted Answer

A)  Instance variables must be declared within a method. 
B)  Instance variables must be declared inside the class, but outside any method. 
C)  Instance variables may be declared inside the class, or inside a method. 
D)  Instance variables must be declared outside the class 
A)  Instance variables must be declared within a method. 
B)  Instance variables must be declared inside the class, but outside any method. 
C)  Instance variables may be declared inside the class, or inside a method. 
D)  Instance variables must be declared outside the class

Question 12

Which of the following statements about encapsulation is correct?

Accepted Answer

A)  To use encapsulation, you must provide a set of private methods in the class. 
B)  To use encapsulation, the class must contain only public methods in the class. 
C)  To use encapsulation, the implementation details must be public. 
D)  To use encapsulation, you must provide a set of public methods in the class and hide the implementation details. 
A)  To use encapsulation, you must provide a set of private methods in the class. 
B)  To use encapsulation, the class must contain only public methods in the class. 
C)  To use encapsulation, the implementation details must be public. 
D)  To use encapsulation, you must provide a set of public methods in the class and hide the implementation details.

Question 13

Which of the following statements about constructors is correct?

Accepted Answer

A)  A class can have only one constructor. 
B)  A constructor should always return a value. 
C)  A class must have at least one constructor supplied by the programmer. 
D)  A constructor must have the same name as the class. 
A)  A class can have only one constructor. 
B)  A constructor should always return a value. 
C)  A class must have at least one constructor supplied by the programmer. 
D)  A constructor must have the same name as the class.

Question 14

Consider the following code snippet:
Public int getSalary(String empNum)
{ ) . . }
Which of the following statements is correct?

Accepted Answer

A)  empNum is an implicit parameter. 
B)  empNum is an explicit parameter. 
C)  empNum is the object on which this method is invoked. 
D)  empNum is an instance variable. 
A)  empNum is an implicit parameter. 
B)  empNum is an explicit parameter. 
C)  empNum is the object on which this method is invoked. 
D)  empNum is an instance variable.

Question 15

Given the following class definition, which of the following are considered part of the class's public interface?
Public class CashRegister
{
Public static final double DIME_VALUE = 0.1;
Private static int objectCounter;
Public void updateDimes(int dimes) {. . .}
Private boolean updateCounter(int counter) {. . .}
}

Accepted Answer

A)  objectCounter and updateCounter 
B)  DIME_VALUE and objectCounter 
C)  DIME_VALUE and updateDimes 
D)  updateDimes and updateCounter 
A)  objectCounter and updateCounter 
B)  DIME_VALUE and objectCounter 
C)  DIME_VALUE and updateDimes 
D)  updateDimes and updateCounter

Question 16

The this reference refers to ____.

Accepted Answer

A)  the explicit parameter 
B)  the method that is running 
C)  the constructor of the object 
D)  the implicit parameter 
A)  the explicit parameter 
B)  the method that is running 
C)  the constructor of the object 
D)  the implicit parameter

Question 17

Given the following class:
Public class Coin
{
Private String coinName;
Private double coinValue;
) . .
}
Consider the following code snippet that utilizes the Coin class:
Coin coin1 = new Coin("dime", 0.10);
Coin coin2 = coin1;
Coin2.setValue(0.15);
Which of the following statements is correct?

Accepted Answer

A)  coin1 has a value of 0.10 and coin2 has a value of 0.15. 
B)  coin1 and coin2 both have the value of 0.10. 
C)  coin1 and coin2 both have the value of 0.15. 
D)  coin2 does not have any data in the coinName variable 
A)  coin1 has a value of 0.10 and coin2 has a value of 0.15. 
B)  coin1 and coin2 both have the value of 0.10. 
C)  coin1 and coin2 both have the value of 0.15. 
D)  coin2 does not have any data in the coinName variable

Question 18

Consider the following code snippet:
Coin coin1 = null;
System.out.println("Value of coin = " + coin1.getValue());
What is wrong with this code?

Accepted Answer

A)  coin1 does not refer to an object and will result in an error at run time. 
B)  You cannot concatenate a numeric value with a string value. 
C)  The value variable in coin1 has not been set, and will print as 0. 
D)  There is nothing wrong with this code. 
A)  coin1 does not refer to an object and will result in an error at run time. 
B)  You cannot concatenate a numeric value with a string value. 
C)  The value variable in coin1 has not been set, and will print as 0. 
D)  There is nothing wrong with this code.

Question 19

Consider the following code snippet:
Public class Employee
{
Private String empID;
Private boolean hourly;
Public Employee()
{
}
) . .
}
Which statement reflects the action performed when the constructor to Employee is called?

Accepted Answer

A)  The variable empID will be initialized to "" and the variable hourly will be initialized to false. 
B)  The variable empID will be initialized to "null" and the variable hourly will be initialized to true. 
C)  The variable empID will not be initialized but the variable hourly will be initialized to false. 
D)  The variable empID will be initialized to null and the variable hourly will be initialized to false. 
A)  The variable empID will be initialized to "" and the variable hourly will be initialized to false. 
B)  The variable empID will be initialized to "null" and the variable hourly will be initialized to true. 
C)  The variable empID will not be initialized but the variable hourly will be initialized to false. 
D)  The variable empID will be initialized to null and the variable hourly will be initialized to false.

Question 20

Data required for an object's use are stored in ____.

Accepted Answer

A)  local variables 
B)  instance variables 
C)  parameters 
D)  methods 
A)  local variables 
B)  instance variables 
C)  parameters 
D)  methods

Exam 8: Objects and Classes

The ____ operator is used to construct an object from a class.

Insert the missing code in the following code fragment. This fragment is intended to implement a method to set the value stored in an instance variable. Public class Employee { Private String empID; Private boolean hourly; ) . . _______ { Hourly = isHourly; } }

Which of the following statements about instance methods is correct?

Consider the following code snippet: Coin coin1 = new Coin("dime", 0.10); Coin coin2 = coin1; Which of the following statements is NOT correct?

The process of hiding object data and providing methods for data access is called ____.

Consider the following code snippet: Public int getCoinValue(String coinName) { ) . . } Which of the following statements is correct?

Given the following class definition, which of the following are considered part of the class's public interface? Public class Motorcycle { Public static final int WHEEL_COUNT = 2; Private int rpmRating; Public void updatePrice(double increase) {…} Private String designCode() {…} }

Which of the following statements about classes is correct?

Which statement about instance variables is correct?

Which of the following statements about encapsulation is correct?

Which of the following statements about constructors is correct?

Consider the following code snippet: Public int getSalary(String empNum) { ) . . } Which of the following statements is correct?

The this reference refers to ____.

Given the following class: Public class Coin { Private String coinName; Private double coinValue; ) . . } Consider the following code snippet that utilizes the Coin class: Coin coin1 = new Coin("dime", 0.10); Coin coin2 = coin1; Coin2.setValue(0.15); Which of the following statements is correct?

Consider the following code snippet: Coin coin1 = null; System.out.println("Value of coin = " + coin1.getValue()); What is wrong with this code?

Consider the following code snippet: Public class Employee { Private String empID; Private boolean hourly; Public Employee() { } ) . . } Which statement reflects the action performed when the constructor to Employee is called?

Data required for an object's use are stored in ____.

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