Question 1

Having a this reference allows:

Accepted Answer

A)  a method to refer explicitly to the instance variables and other methods of the object on which the method was called. 
B)  a method to refer implicitly to the instance variables and other methods of the object on which the method was called. 
C)  an object to reference itself. 
D)  All of the above. 
A)  a method to refer explicitly to the instance variables and other methods of the object on which the method was called. 
B)  a method to refer implicitly to the instance variables and other methods of the object on which the method was called. 
C)  an object to reference itself. 
D)  All of the above. D

Question 2

Which statement is false?

Accepted Answer

A)  An enum declaration is a comma-separated list of enum constants and may optionally include other components of traditional classes, such as constructors, fields and methods. 
B)  Any attempt to create an object of an enum type with operator new results in a compilation error. 
C)  An enum constructor cannot be overloaded. 
D)  enum constants are implicitly final and static. 
A)  An enum declaration is a comma-separated list of enum constants and may optionally include other components of traditional classes, such as constructors, fields and methods. 
B)  Any attempt to create an object of an enum type with operator new results in a compilation error. 
C)  An enum constructor cannot be overloaded. 
D)  enum constants are implicitly final and static. C

Question 3

A constructor cannot:

Accepted Answer

A)  be overloaded. 
B)  initialize variables to their defaults. 
C)  specify return types or return values. 
D)  have the same name as the class. 
A)  be overloaded. 
B)  initialize variables to their defaults. 
C)  specify return types or return values. 
D)  have the same name as the class. C

Question 4

When implementing a method, use the class's set and get methods to access the class's ________ data.

Accepted Answer

A)  public. 
B)  private. 
C)  protected. 
D)  All of the above. 
A)  public. 
B)  private. 
C)  protected. 
D)  All of the above.

Question 5

Which of the following statements is true?

Accepted Answer

A)  Methods and instance variables can both be either public or private. 
B)  Information hiding is achieved by restricting access to class members via keyword public. 
C)  The private members of a class are directly accessible to the clients of a class. 
D)  None of the above is true. 
A)  Methods and instance variables can both be either public or private. 
B)  Information hiding is achieved by restricting access to class members via keyword public. 
C)  The private members of a class are directly accessible to the clients of a class. 
D)  None of the above is true.

Question 6

Using public set methods helps provide data integrity if:

Accepted Answer

A)  The instance variables are public. 
B)  The instance variables are private. 
C)  The methods perform validity checking. 
D)  Both b and c. 
A)  The instance variables are public. 
B)  The instance variables are private. 
C)  The methods perform validity checking. 
D)  Both b and c.

Question 7

Which method returns an array of the enum's constants?

Accepted Answer

A)  values. 
B)  getValues. 
C)  constants. 
D)  getConstants. 
A)  values. 
B)  getValues. 
C)  constants. 
D)  getConstants.

Question 8

The _________ of a class are also called the public services or the public interface that the class provides to its clients.

Accepted Answer

A)  public constructors. 
B)  public instance variables. 
C)  public methods. 
D)  All of the above. 
A)  public constructors. 
B)  public instance variables. 
C)  public methods. 
D)  All of the above.

Question 9

Which of the following is false?

Accepted Answer

A)  A static method must be used to access private static instance variables. 
B)  A static method has no this reference. 
C)  A static method can be accessed even when no objects of its class have been instantiated. 
D)  A static method can call instance methods directly. 
A)  A static method must be used to access private static instance variables. 
B)  A static method has no this reference. 
C)  A static method can be accessed even when no objects of its class have been instantiated. 
D)  A static method can call instance methods directly.

Question 10

When must a program explicitly use the this reference?

Accepted Answer

A)  Accessing a private variable. 
B)  Accessing a public variable. 
C)  Accessing a local variable. 
D)  Accessing an instance variable that is shadowed by a local variable. 
A)  Accessing a private variable. 
B)  Accessing a public variable. 
C)  Accessing a local variable. 
D)  Accessing an instance variable that is shadowed by a local variable.

Question 11

When no access modifier is specified for a method or variable, the method or variable:

Accepted Answer

A)  Is public. 
B)  Is private. 
C)  Has package access. 
D)  Is static. 
A)  Is public. 
B)  Is private. 
C)  Has package access. 
D)  Is static.

Question 12

Which statement is false?

Accepted Answer

A)  The actual data representation used within the class is of no concern to the class's clients. 
B)  Clients generally care about what the class does but not how the class does it. 
C)  Clients are usually involved in a class's implementation. 
D)  Hiding the implementation reduces the possibility that clients will become dependent on class-implementation details. 
A)  The actual data representation used within the class is of no concern to the class's clients. 
B)  Clients generally care about what the class does but not how the class does it. 
C)  Clients are usually involved in a class's implementation. 
D)  Hiding the implementation reduces the possibility that clients will become dependent on class-implementation details.

Question 13

Instance variables declared final do not or cannot:

Accepted Answer

A)  Cause syntax errors if used as a left-hand value. 
B)  Be initialized. 
C)  Be modified after they are initialized. 
D)  None of the above. 
A)  Cause syntax errors if used as a left-hand value. 
B)  Be initialized. 
C)  Be modified after they are initialized. 
D)  None of the above.

Question 14

Set methods are also commonly called ________ methods and get methods are also commonly called ________ methods.

Accepted Answer

A)  query, mutator. 
B)  accessor, mutator. 
C)  mutator, accessor. 
D)  query, accessor. 
A)  query, mutator. 
B)  accessor, mutator. 
C)  mutator, accessor. 
D)  query, accessor.

Question 15

A programmer-defined constructor that has no arguments is called a(n) ________.

Accepted Answer

A)  empty constructor. 
B)  no-argument constructor. 
C)  default constructor. 
D)  null constructor. 
A)  empty constructor. 
B)  no-argument constructor. 
C)  default constructor. 
D)  null constructor.

Question 16

What happens when this is used in a constructor's body to call another constructor of the same class if that call is not the first statement in the constructor?

Accepted Answer

A)  A compilation error occurs. 
B)  A runtime error occurs. 
C)  A logic error occurs. 
D)  Nothing happens. The program compiles and runs. 
A)  A compilation error occurs. 
B)  A runtime error occurs. 
C)  A logic error occurs. 
D)  Nothing happens. The program compiles and runs.

Question 17

Which of the following is false?

Accepted Answer

A)  Method finalize does not take parameters and has return type void. 
B)  Memory leaks using Java are rare because of automatic garbage collection. 
C)  Objects are marked for garbage collection by method finalize. 
D)  The garbage collector reclaims unused memory. 
A)  Method finalize does not take parameters and has return type void. 
B)  Memory leaks using Java are rare because of automatic garbage collection. 
C)  Objects are marked for garbage collection by method finalize. 
D)  The garbage collector reclaims unused memory.

Question 18

The static method ________ of class String returns a formatted String.

Accepted Answer

A)  printf. 
B)  format. 
C)  formatString. 
D)  toFormatedString. 
A)  printf. 
B)  format. 
C)  formatString. 
D)  toFormatedString.

Question 19

A final field should also be declared ________ if it is initialized in its declaration.

Accepted Answer

A)  private. 
B)  public. 
C)  protected. 
D)  static. 
A)  private. 
B)  public. 
C)  protected. 
D)  static.

Question 20

Constructors:

Accepted Answer

A)  Initialize instance variables. 
B)  When overloaded, can have identical argument lists. 
C)  When overloaded, are selected by number, types and order of types of parameters. 
D)  Both (a) and (c). 
A)  Initialize instance variables. 
B)  When overloaded, can have identical argument lists. 
C)  When overloaded, are selected by number, types and order of types of parameters. 
D)  Both (a) and (c).

Exam 8: Classes and Objects: a Deeper Look

Having a this reference allows:

Which statement is false?

A constructor cannot:

When implementing a method, use the class's set and get methods to access the class's ________ data.

Which of the following statements is true?

Using public set methods helps provide data integrity if:

Which method returns an array of the enum's constants?

The _________ of a class are also called the public services or the public interface that the class provides to its clients.

Which of the following is false?

When must a program explicitly use the this reference?

When no access modifier is specified for a method or variable, the method or variable:

Which statement is false?

Instance variables declared final do not or cannot:

Set methods are also commonly called ________ methods and get methods are also commonly called ________ methods.

A programmer-defined constructor that has no arguments is called a(n) ________.

What happens when this is used in a constructor's body to call another constructor of the same class if that call is not the first statement in the constructor?

Which of the following is false?

The static method ________ of class String returns a formatted String.

A final field should also be declared ________ if it is initialized in its declaration.

Constructors:

Introduction to Computers and Java

Introduction to Java Applications

Control Statements

Control Statements

Methods

Arrays and Arraylists

Introduction to Classes and Objects

Object Oriented Programming: Inheritance

Object-Oriented Programming: Polymorphism

Exception Handling

Gui Components

Graphics and Java 2D

Fundamentals of Characters and Strings

Files, Streams and Object Serialization

Generic Collections

Lambdas

Recursion

Searching, Sorting and Big O

Generic Classes and Methods

Custom Generic Data Structures

GUI

Concurrency

Accessing Databases With JDBC

JavaFX

Filters

Set methods are also commonly called methods and get methods are also commonly called methods.