Question 1

Which of the following statements is true?

Accepted Answer

A)  The UML models a parameter of an operation by listing the parameter name, followed by a colon and the parameter value between the parentheses after the operation name. 
B)  The UML indicates an operation's return type by placing a colon and the return value after the parentheses following the operation name. 
C)  UML class diagrams do not specify return types for operations that do not return values. 
D)  Declaring instance variables public is known as data hiding or information hiding. 
A)  The UML models a parameter of an operation by listing the parameter name, followed by a colon and the parameter value between the parentheses after the operation name. 
B)  The UML indicates an operation's return type by placing a colon and the return value after the parentheses following the operation name. 
C)  UML class diagrams do not specify return types for operations that do not return values. 
D)  Declaring instance variables public is known as data hiding or information hiding. C

Question 2

How many Book objects are created by the following statement?
Book[] books = new Book[10];

Accepted Answer

A)  10 
B)  0 
C)  5 
D)  None of the above. 
A)  10 
B)  0 
C)  5 
D)  None of the above. B

Question 3

Each class you create becomes a new ________ that can be used to declare variables and create objects.

Accepted Answer

A)  package 
B)  instance 
C)  library 
D)  type. 
A)  package 
B)  instance 
C)  library 
D)  type. D

Question 4

Declaring instance variables ________ is known as data hiding or information hiding.

Accepted Answer

A)  secure 
B)  private 
C)  static 
D)  masked 
A)  secure 
B)  private 
C)  static 
D)  masked

Question 5

A static method can ________.

Accepted Answer

A)  call only other static methods of the same class directly 
B)  manipulate only static fields in the same class directly 
C)  be called using the class name and a dot (.) 
D)  All of the above. 
A)  call only other static methods of the same class directly 
B)  manipulate only static fields in the same class directly 
C)  be called using the class name and a dot (.) 
D)  All of the above.

Question 6

Consider integer array values, which contains 5 elements. Which statements successfully swap the contents of the array at index 3 and index 4?

Accepted Answer

A)  values[3] = values[4];
Values[4] = values[3]; 
B)  values[4] = values[3];
Values[3] = values[4]; 
C)  int temp = values[3];
Values[3] = values[4];
Values[4] = temp; 
D)  int temp = values[3];
Values[3] = values[4];
Values[4] = values[3]; 
A)  values[3] = values[4];
Values[4] = values[3]; 
B)  values[4] = values[3];
Values[3] = values[4]; 
C)  int temp = values[3];
Values[3] = values[4];
Values[4] = temp; 
D)  int temp = values[3];
Values[3] = values[4];
Values[4] = values[3];

Question 7

Which of the following statements is false?

Accepted Answer

A)  The method's return type specifies the type of data returned to a method's caller. 
B)  Empty parentheses following a method name indicate that the method does not require any parameters to perform its task. 
C)  When a method that specifies a return type other than void is called and completes its task, the method must return a result to its calling method 
D)  Classes often provide public methods to allow the class's clients to set or get private instance variables; the names of these methods must begin with set or get. 
A)  The method's return type specifies the type of data returned to a method's caller. 
B)  Empty parentheses following a method name indicate that the method does not require any parameters to perform its task. 
C)  When a method that specifies a return type other than void is called and completes its task, the method must return a result to its calling method 
D)  Classes often provide public methods to allow the class's clients to set or get private instance variables; the names of these methods must begin with set or get.

Question 8

What kind of application tests a class by creating an object of that class and calling the class's methods?

Accepted Answer

A)  Pseudo application. 
B)  Debugger. 
C)  Declarator. 
D)  Test harness. 
A)  Pseudo application. 
B)  Debugger. 
C)  Declarator. 
D)  Test harness.

Question 9

Which of the following statements is false?

Accepted Answer

A)  Each class declaration that begins with the access modifier private must be stored in a file that has the same name as the class and ends with the .java filename extension. 
B)  Every class declaration contains keyword class followed immediately by the class's name. 
C)  Class, method and variable names are identifiers. 
D)  An object has attributes that are implemented as instance variables and carried with it throughout its lifetime. 
A)  Each class declaration that begins with the access modifier private must be stored in a file that has the same name as the class and ends with the .java filename extension. 
B)  Every class declaration contains keyword class followed immediately by the class's name. 
C)  Class, method and variable names are identifiers. 
D)  An object has attributes that are implemented as instance variables and carried with it throughout its lifetime.

Question 10

A __________ of a class called myClass is another class whose methods call the methods of myClass.

Accepted Answer

A)  consumer 
B)  servant 
C)  caller 
D)  client 
A)  consumer 
B)  servant 
C)  caller 
D)  client

Question 11

Which of the following statements is true?

Accepted Answer

A)  Each object (instance) of the class shares the class's instance variables. 
B)  Most instance-variable declarations are preceded with the keyword public, which is an access modifier. 
C)  Variables or methods declared with access modifier private are accessible only to methods of the class in which they're declared. 
D)  None of the above is true. 
A)  Each object (instance) of the class shares the class's instance variables. 
B)  Most instance-variable declarations are preceded with the keyword public, which is an access modifier. 
C)  Variables or methods declared with access modifier private are accessible only to methods of the class in which they're declared. 
D)  None of the above is true.

Question 12

Which of the following statements is true?

Accepted Answer

A)  Local variables are automatically initialized. 
B)  Every instance variable has a default initial value-a value provided by Java when you do not specify the instance variable's initial value. 
C)  The default value for an instance variable of type String is void. 
D)  The argument types in the method call must be identical to the types of the corresponding parameters in the method's declaration. 
A)  Local variables are automatically initialized. 
B)  Every instance variable has a default initial value-a value provided by Java when you do not specify the instance variable's initial value. 
C)  The default value for an instance variable of type String is void. 
D)  The argument types in the method call must be identical to the types of the corresponding parameters in the method's declaration.

Question 13

Assume class Book has been declared. Which set of statements creates an array of Books?

Accepted Answer

A)  Book[] books;
Books = new Book[numberElements]; 
B)  Book[] books];
Books = new Book()[numberElements]; 
C)  new Book() books[];
Books = new Book[numberElements]; 
D)  All of the above. 
A)  Book[] books;
Books = new Book[numberElements]; 
B)  Book[] books];
Books = new Book()[numberElements]; 
C)  new Book() books[];
Books = new Book[numberElements]; 
D)  All of the above.

Question 14

Which of the following statements is true?

Accepted Answer

A)  Constructors can specify parameters and return types. 
B)  Constructors can specify parameters but not return types. 
C)  Constructors cannot specify parameters but can specify return types. 
D)  Constructors can specify neither parameters nor return types. 
A)  Constructors can specify parameters and return types. 
B)  Constructors can specify parameters but not return types. 
C)  Constructors cannot specify parameters but can specify return types. 
D)  Constructors can specify neither parameters nor return types.

Question 15

The format specifier %.2f specifies that two digits of precision should be output ________ in the floating-point number.

Accepted Answer

A)  to the left of the decimal point 
B)  centered 
C)  to the right of the decimal point 
D)  None of the above. 
A)  to the left of the decimal point 
B)  centered 
C)  to the right of the decimal point 
D)  None of the above.

Question 16

When a method terminates, the values of its local variables are ________.

Accepted Answer

A)  saved 
B)  copied 
C)  restored 
D)  lost 
A)  saved 
B)  copied 
C)  restored 
D)  lost

Question 17

Which of the following statements is false?

Accepted Answer

A)  Scanner method next reads characters until any white-space character is encountered, then returns the characters as a String. 
B)  To call a method of an object, follow the object name with a comma, the method name and a set of parentheses containing the method's arguments. 
C)  A class instance creation expression begins with keyword new and creates a new object. 
D)  A constructor is similar to a method but is called implicitly by the new operator to initialize an object's instance variables at the time the object is created. 
A)  Scanner method next reads characters until any white-space character is encountered, then returns the characters as a String. 
B)  To call a method of an object, follow the object name with a comma, the method name and a set of parentheses containing the method's arguments. 
C)  A class instance creation expression begins with keyword new and creates a new object. 
D)  A constructor is similar to a method but is called implicitly by the new operator to initialize an object's instance variables at the time the object is created.

Question 18

Which of the following statements is false?

Accepted Answer

A)  In the UML, each class is modeled in a class diagram as a rectangle with three compartments. The top one contains the class's name centered horizontally in boldface. The middle one contains the class's attributes, which correspond to instance variables in Java. The bottom one contains the class's operations, which correspond to methods and constructors in Java. 
B)  UML represents instance variables as an attribute name, followed by a colon and the type. 
C)  Private attributes are preceded by the keyword private in the UML. 
D)  The UML models operations by listing the operation name followed by a set of parentheses. A plus sign (+) in front of the operation name indicates that the operation is a public. 
A)  In the UML, each class is modeled in a class diagram as a rectangle with three compartments. The top one contains the class's name centered horizontally in boldface. The middle one contains the class's attributes, which correspond to instance variables in Java. The bottom one contains the class's operations, which correspond to methods and constructors in Java. 
B)  UML represents instance variables as an attribute name, followed by a colon and the type. 
C)  Private attributes are preceded by the keyword private in the UML. 
D)  The UML models operations by listing the operation name followed by a set of parentheses. A plus sign (+) in front of the operation name indicates that the operation is a public.

Question 19

You can declare new classes as needed; this is one reason Java is known as a(n) ________ language.

Accepted Answer

A)  portable 
B)  incremental 
C)  extensible 
D)  virtual 
A)  portable 
B)  incremental 
C)  extensible 
D)  virtual

Question 20

Java requires a ________ call for every object that's created.

Accepted Answer

A)  constructor 
B)  destructor 
C)  parameterless 
D)  parameterized 
A)  constructor 
B)  destructor 
C)  parameterless 
D)  parameterized

Exam 7: Introduction to Classes and Objects

Which of the following statements is true?

How many Book objects are created by the following statement? Book[] books = new Book[10];

Each class you create becomes a new ________ that can be used to declare variables and create objects.

Declaring instance variables ________ is known as data hiding or information hiding.

A static method can ________.

Consider integer array values, which contains 5 elements. Which statements successfully swap the contents of the array at index 3 and index 4?

Which of the following statements is false?

What kind of application tests a class by creating an object of that class and calling the class's methods?

Which of the following statements is false?

A __________ of a class called myClass is another class whose methods call the methods of myClass.

Which of the following statements is true?

Which of the following statements is true?

Assume class Book has been declared. Which set of statements creates an array of Books?

Which of the following statements is true?

The format specifier %.2f specifies that two digits of precision should be output ________ in the floating-point number.

When a method terminates, the values of its local variables are ________.

Which of the following statements is false?

Which of the following statements is false?

You can declare new classes as needed; this is one reason Java is known as a(n) ________ language.

Java requires a ________ call for every object that's created.

Introduction to Computers and Java

Introduction to Java Applications

Control Statements

Control Statements

Methods

Arrays and Arraylists

Classes and Objects: a Deeper Look

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