Question 1

An instance variable declaration consists of ____.

Accepted Answer

A)  the return type, the name of the method, and a list of the parameters (if any). 
B)  an access specifier, the type of the instance variable, and the name of the instance variable. 
C)  an access specifier, a list of the parameters (if any), and the body of the method. 
D)  the type of the instance variable, an access specifier, a list of the parameters (if any), and the body of the method. 
A)  the return type, the name of the method, and a list of the parameters (if any). 
B)  an access specifier, the type of the instance variable, and the name of the instance variable. 
C)  an access specifier, a list of the parameters (if any), and the body of the method. 
D)  the type of the instance variable, an access specifier, a list of the parameters (if any), and the body of the method. B

Question 2

Which of the following lists the correct order of items in an instance method declaration?

Accepted Answer

A)  the return type, the name of the method, and a list of the parameters (if any) 
B)  modifiers, the type of the instance variable, and the name of the instance variable 
C)  the type of the instance variable, modifiers, and a list of the parameters (if any) 
D)  modifiers, a return type, a method name, and a list of the parameters (if any) 
A)  the return type, the name of the method, and a list of the parameters (if any) 
B)  modifiers, the type of the instance variable, and the name of the instance variable 
C)  the type of the instance variable, modifiers, and a list of the parameters (if any) 
D)  modifiers, a return type, a method name, and a list of the parameters (if any) D

Question 3

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

Accepted Answer

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

Question 4

Insert the missing code in the following code fragment. This fragment is intended to implement a method to get the value stored in an instance variable.
Public class Vehicle
{
Private String model;
Private double rpm;
) . .
_______
{
Return model;
}
}

Accepted Answer

A)  public void setModel(String modelName) 
B)  public void getModel() 
C)  public String getModel() 
D)  public String setModel(String modelName) 
A)  public void setModel(String modelName) 
B)  public void getModel() 
C)  public String getModel() 
D)  public String setModel(String modelName)

Question 5

You have created a Coin class and a Purse class. Which of the following methods will correctly add a Coin object to an array list named coins in the Purse class?

Accepted Answer

A)  public void add(Coin aCoin)
{
Coins.add(new Coin(aCoin));
} 
B)  public void add(Coin aCoin)
{
Coins.add(aCoin);
} 
C)  public void add(Coin aCoin)
{
Coins.addItem(new Coin(aCoin));
} 
D)  public void add(Coin aCoin)
{
Coins.addItem(aCoin);
} 
A)  public void add(Coin aCoin)
{
Coins.add(new Coin(aCoin));
} 
B)  public void add(Coin aCoin)
{
Coins.add(aCoin);
} 
C)  public void add(Coin aCoin)
{
Coins.addItem(new Coin(aCoin));
} 
D)  public void add(Coin aCoin)
{
Coins.addItem(aCoin);
}

Question 6

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 this class is correct?

Accepted Answer

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

Question 7

Given the following class definition, which of the following are NOT 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 8

The utility that formats program comments into a set of documents that you can view in a Web browser is called ____.

Accepted Answer

A)  javadoc 
B)  javac 
C)  javad 
D)  java 
A)  javadoc 
B)  javac 
C)  javad 
D)  java

Question 9

Which of the following statements about classes is correct?

Accepted Answer

A)  All instance variables and most instance methods should be declared as public. 
B)  All instance variables and most instance methods should be declared as private. 
C)  All instance variables should be declared as public and most instance methods should be declared as private. 
D)  All instance variables should be declared as private and most instance methods should be declared as public. 
A)  All instance variables and most instance methods should be declared as public. 
B)  All instance variables and most instance methods should be declared as private. 
C)  All instance variables should be declared as public and most instance methods should be declared as private. 
D)  All instance variables should be declared as private and most instance methods should be declared as public.

Question 10

Consider the following code snippet:
Coin coin1 = new Coin("dime", 0.10);
Coin coin2 = new Coin("dime", 0.10);
Which of the following statements is correct?

Accepted Answer

A)  coin1 and coin2 contain references to the same object. 
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 contain references to the same object. 
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 11

You should declare all instance variables as ___.

Accepted Answer

A)  protected 
B)  class 
C)  public 
D)  private 
A)  protected 
B)  class 
C)  public 
D)  private

Question 12

Which of the following statements about testing a class is correct?

Accepted Answer

A)  A unit test verifies that only one method within a class works correctly. 
B)  A unit test verifies that a class works correctly when it is in a complete program. 
C)  A unit test verifies that a class works correctly in isolation, outside a complete program. 
D)  A unit test does not need to know what results are expected. 
A)  A unit test verifies that only one method within a class works correctly. 
B)  A unit test verifies that a class works correctly when it is in a complete program. 
C)  A unit test verifies that a class works correctly in isolation, outside a complete program. 
D)  A unit test does not need to know what results are expected.

Question 13

The public constructors and methods of a class form the public _____ of the class.

Accepted Answer

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

Question 14

Insert the missing code in the following code fragment. This fragment is intended to implement a method to assign a value to an instance variable.
Public class Vehicle
{
Private String model;
Private double rpm;
) . .
_______
{
Model = modelName;
}
}

Accepted Answer

A)  public void setModel(String modelName) 
B)  public void getModel() 
C)  public String getModel() 
D)  public String setModel(String modelName) 
A)  public void setModel(String modelName) 
B)  public void getModel() 
C)  public String getModel() 
D)  public String setModel(String modelName)

Question 15

Insert the missing code in the following code fragment. This fragment is intended to initialize an instance variable.
Public class Motor
{
Int motorSpeed;
Public Motor(int speed)
{
MotorSpeed = speed;
}
Public Motor()
{
_________;
}
}
Which of the following lines of code will allow the second constructor to call the first constructor?

Accepted Answer

A)  this.motorspeed(0); 
B)  this(0); 
C)  this(speed); 
D)  You cannot call a constructor from within another constructor. 
A)  this.motorspeed(0); 
B)  this(0); 
C)  this(speed); 
D)  You cannot call a constructor from within another constructor.

Question 16

Which operator should you use to test whether an object reference is null?

Accepted Answer

A) == B) >= C) <= D) = A) == B) >= C) <= D) =

Question 17

Which statement illustrates the invocation of a static method?

Accepted Answer

A)  mySavings.deposit(100); 
B)  double s = Math.sqrt(100); 
C)  deposit(100).mySavings; 
D)  double s = 100.sqrt(); 
A)  mySavings.deposit(100); 
B)  double s = Math.sqrt(100); 
C)  deposit(100).mySavings; 
D)  double s = 100.sqrt();

Question 18

Which type of method modifies the object on which it is invoked?

Accepted Answer

A)  Constructor method. 
B)  Static method. 
C)  Accessor method. 
D)  Mutator method. 
A)  Constructor method. 
B)  Static method. 
C)  Accessor method. 
D)  Mutator method.

Question 19

Complete the following code snippet to create a constructor that will initialize the class instance variables shown using data provided by the program which is creating an object from this class.
Public class Employee
{
Private String empID;
Private boolean hourly;
_______________________
{ ) . . }
}
Which of the following statements can be used to create an object of type Employee?

Accepted Answer

A)  public Employee(String employeeID, boolean isHourly) 
B)  public Employee(employeeID, isHourly) 
C)  public Employee(empID, Hourly) 
D)  public Employee() 
A)  public Employee(String employeeID, boolean isHourly) 
B)  public Employee(employeeID, isHourly) 
C)  public Employee(empID, Hourly) 
D)  public Employee()

Question 20

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

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)

Exam 8: Objects and Classes

An instance variable declaration consists of ____.

Which of the following lists the correct order of items in an instance method declaration?

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

Insert the missing code in the following code fragment. This fragment is intended to implement a method to get the value stored in an instance variable. Public class Vehicle { Private String model; Private double rpm; ) . . _______ { Return model; } }

You have created a Coin class and a Purse class. Which of the following methods will correctly add a Coin object to an array list named coins in the Purse class?

Given the following class definition, which of the following are NOT 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() {…} }

The utility that formats program comments into a set of documents that you can view in a Web browser is called ____.

Which of the following statements about classes is correct?

Consider the following code snippet: Coin coin1 = new Coin("dime", 0.10); Coin coin2 = new Coin("dime", 0.10); Which of the following statements is correct?

You should declare all instance variables as ___.

Which of the following statements about testing a class is correct?

The public constructors and methods of a class form the public _____ of the class.

Insert the missing code in the following code fragment. This fragment is intended to implement a method to assign a value to an instance variable. Public class Vehicle { Private String model; Private double rpm; ) . . _______ { Model = modelName; } }

Which operator should you use to test whether an object reference is null?

Which statement illustrates the invocation of a static method?

Which type of method modifies the object on which it is invoked?

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

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