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 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. A

Question 3

Which of the following statements is false?

Accepted Answer

A)  If a program uses multiple classes from the same package, these classes can access each other's package access members directly through references to objects of the appropriate classes, or in the case of static members, through the class name. 
B)  Package access is rarely used. 
C)  Classes in the same source file are part of the same package. 
D)  Use the access modifier package to give a method or variable package access. 
A)  If a program uses multiple classes from the same package, these classes can access each other's package access members directly through references to objects of the appropriate classes, or in the case of static members, through the class name. 
B)  Package access is rarely used. 
C)  Classes in the same source file are part of the same package. 
D)  Use the access modifier package to give a method or variable package access. D

Question 4

Static class variables:

Accepted Answer

A)  are final. 
B)  are public. 
C)  are private. 
D)  are shared by all objects of a class. 
A)  are final. 
B)  are public. 
C)  are private. 
D)  are shared by all objects of a class.

Question 5

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 6

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).

Question 7

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 8

Which syntax imports all static members of class Math?

Accepted Answer

A)  import java.lang.Math.*. 
B)  import static java.lang.Math.*. 
C)  import static java.lang.Math. 
D)  None of the above. 
A)  import java.lang.Math.*. 
B)  import static java.lang.Math.*. 
C)  import static java.lang.Math. 
D)  None of the above.

Question 9

Which of the following statements is false?

Accepted Answer

A)  An application that requires precise floating-point calculations such as those in financial applications should use class BigDecimal from package java.math. 
B)  We use class NumberFormat for formatting numeric values as locale-specific strings. 
C)  In the U.S, locale, the value 15467.82 would be formatted as "15,467.82", whereas in many European locales it would be formatted as "15.467,56". 
D)  The BigDecimal method format receives a double argument and returns a BigDecimal object that represents the exact value specied. 
A)  An application that requires precise floating-point calculations such as those in financial applications should use class BigDecimal from package java.math. 
B)  We use class NumberFormat for formatting numeric values as locale-specific strings. 
C)  In the U.S, locale, the value 15467.82 would be formatted as "15,467.82", whereas in many European locales it would be formatted as "15.467,56". 
D)  The BigDecimal method format receives a double argument and returns a BigDecimal object that represents the exact value specied.

Question 10

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.

Question 11

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 12

Which statement is false?

Accepted Answer

A)  The compiler always creates a default constructor for a class. 
B)  If a class's constructors all require arguments and a program attempts to call a no-argument constructor to initialize an object of the class, a compilation error occurs. 
C)  A constructor can be called with no arguments only if the class does not have any constructors or if the class has a public no-argument constructor. 
D)  None of the above. 
A)  The compiler always creates a default constructor for a class. 
B)  If a class's constructors all require arguments and a program attempts to call a no-argument constructor to initialize an object of the class, a compilation error occurs. 
C)  A constructor can be called with no arguments only if the class does not have any constructors or if the class has a public no-argument constructor. 
D)  None of the above.

Question 13

Composition is sometimes referred to as a(n) ________.

Accepted Answer

A)  is-a relationship 
B)  has-a relationship 
C)  many-to-one relationship 
D)  one-to-many relationship 
A)  is-a relationship 
B)  has-a relationship 
C)  many-to-one relationship 
D)  one-to-many relationship

Question 14

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 15

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 16

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.

Question 17

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 18

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 19

BigDecimal gives you control over how values are rounded. By default:

Accepted Answer

A)  all calculations are approximate and no rounding occurs. 
B)  all calculations are approximate and rounding occurs. 
C)  all calculations are exact and no rounding occurs. 
D)  all calculations are exact and rounding occurs. 
A)  all calculations are approximate and no rounding occurs. 
B)  all calculations are approximate and rounding occurs. 
C)  all calculations are exact and no rounding occurs. 
D)  all calculations are exact and rounding occurs.

Question 20

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.

Exam 8: Classes and Objects: a Deeper Look

Having a this reference allows:

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

Which of the following statements is false?

Static class variables:

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

Constructors:

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

Which syntax imports all static members of class Math?

Which of the following statements is false?

A constructor cannot:

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

Which statement is false?

Composition is sometimes referred to as a(n) ________.

Instance variables declared final do not or cannot:

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

Which statement is false?

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

Using public set methods helps provide data integrity if:

BigDecimal gives you control over how values are rounded. By default:

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

Introduction to Computers, the Internet and Java

Introduction to Java Applications; Inputoutput and Operators

Introduction to Classes, Objects, Methods and Strings

Control Statements: Assignment, and Operators

Control Statements: Logical Operators

Methods: a Deeper Look

Arrays and Arraylists

Object-Oriented Programming: Inheritance

Object-Oriented Programming: Polymorphism and Interfaces

Exception Handling: a Deeper Look

Javafx Graphical User Interfaces

Javafx Gui

Strings, Characters and Regular Expressions

Files, Inputoutput Streams, Nio and Xml Serialization

Generic Collections

Lambdas and Streams

Recursion

Searching, Sorting and Big O

Generic Classes and Methods: a Deeper Look

Custom Generic Data Structures

Concurrency

Accessing Databases With Jdbc

Swing Gui Components

Graphics and Java 2d

Networking

Java Persistence Api Jpa

Javaserver Faces Web Apps

Javaserver Faces Web Apps

Swing Gui Components

Filters

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