Question 1

Why does Java provide a protected access modifier?

Accepted Answer

A)  To hide methods from the client classes 
B)  To hide fields from client classes 
C)  So that fields and methods can be inherited by subclasses 
D)  All of these are correct. 
A)  To hide methods from the client classes 
B)  To hide fields from client classes 
C)  So that fields and methods can be inherited by subclasses 
D)  All of these are correct. D

Question 2

An interface can contain one or more abstract methods.

Accepted Answer

A) True 
 B)False  True

Question 3

Assuming that class B inherits from class A and method foo belongs to class A, what do we mean by overriding method foo in class B?

Accepted Answer

A)  We are calling method foo in class B. 
B)  We are not using method foo in class B. 
C)  We are replacing the superclass version of the foo method with a new foo method with the same signature. 
A)  We are calling method foo in class B. 
B)  We are not using method foo in class B. 
C)  We are replacing the superclass version of the foo method with a new foo method with the same signature. C

Question 4

Abstract methods can be static.

Accepted Answer

A) True 
 B)False

Question 5

When is it determined which method is called when using polymorphism?

Accepted Answer

A)  At compile time 
B)  At the time of writing code 
C)  At runtime 
A)  At compile time 
B)  At the time of writing code 
C)  At runtime

Question 6

An abstract method:

Accepted Answer

A)  has a "do-nothing" body. 
B)  does not have a body. 
C)  has a body that operates like any other method. 
A)  has a "do-nothing" body. 
B)  does not have a body. 
C)  has a body that operates like any other method.

Question 7

Typically, an abstract class is a class that is not completely implemented.

Accepted Answer

A) True 
 B)False

Question 8

What keyword do we use in the class header that inherits from an interface?

Accepted Answer

A)  inherits 
B)  interfaces 
C)  implements 
D)  modifies 
A)  inherits 
B)  interfaces 
C)  implements 
D)  modifies

Question 9

To use polymorphism, the classes must be in a different hierarchy.

Accepted Answer

A) True 
 B)False

Question 10

Inheritance is useful for which of the following?

Accepted Answer

A)  It declares the hierarchy of methods that are not common to all classes so they can be reused. 
B)  It allows superclasses to override subclasses. 
C)  It allows related classes to be organized into levels of functionality so they can be reused. 
D)  None of these is correct. 
A)  It declares the hierarchy of methods that are not common to all classes so they can be reused. 
B)  It allows superclasses to override subclasses. 
C)  It allows related classes to be organized into levels of functionality so they can be reused. 
D)  None of these is correct.

Question 11

Overriding a method and overloading a method mean the same thing.

Accepted Answer

A) True 
 B)False

Question 12

The following code will run without errors:
// Figure is an abstract class
Figure f = new Figure( );

Accepted Answer

A) True 
 B)False

Question 13

An abstract class is declared to be abstract by including the __________ keyword in the class header.

Accepted Answer

The answer of An abstract class is declared to be...

Question 14

A class can implement more than one interface.

Accepted Answer

A) True 
 B)False

Question 15

_________ allows us to use the same method call for any object in a class hierarchy.

Accepted Answer

The answer of _________ allows us to use the same...

Question 16

You have written a SavingsAccount class based on the BankAccount class in the textbook. You wish to instantiate a SavingsAccount object with a starting balance of $2,175.25. Theorize why you would need to provide an overloaded constructor for the SavingsAccount class.

Accepted Answer

The default constructor of the BankAccou

Question 17

Public fields and methods are inherited.

Accepted Answer

A) True 
 B)False

Question 18

The extends keyword specifies that the subclass inherits members of the superclass.

Accepted Answer

A) True 
 B)False

Question 19

The interface concept is Java's way of implementing __________ inheritance.

Accepted Answer

The answer of The interface concept is Java's way of...

Question 20

When a class extends another class, the default constructor of the subclass automatically calls the default constructor of the superclass. This is called explicit invocation.

Accepted Answer

A) True 
 B)False

Why does Java provide a protected access modifier?

An interface can contain one or more abstract methods.

Assuming that class B inherits from class A and method foo belongs to class A, what do we mean by overriding method foo in class B?

Abstract methods can be static.

When is it determined which method is called when using polymorphism?

An abstract method:

Typically, an abstract class is a class that is not completely implemented.

What keyword do we use in the class header that inherits from an interface?

To use polymorphism, the classes must be in a different hierarchy.

Inheritance is useful for which of the following?

Overriding a method and overloading a method mean the same thing.

The following code will run without errors: // Figure is an abstract class Figure f = new Figure( );

An abstract class is declared to be abstract by including the __________ keyword in the class header.

A class can implement more than one interface.

_________ allows us to use the same method call for any object in a class hierarchy.

You have written a SavingsAccount class based on the BankAccount class in the textbook. You wish to instantiate a SavingsAccount object with a starting balance of $2,175.25. Theorize why you would need to provide an overloaded constructor for the SavingsAccount class.

Public fields and methods are inherited.

The extends keyword specifies that the subclass inherits members of the superclass.

The interface concept is Java's way of implementing __________ inheritance.

When a class extends another class, the default constructor of the subclass automatically calls the default constructor of the superclass. This is called explicit invocation.

Introduction to Programming and the Java Language

Programming Building Blocks- Java Basics

Object-Oriented Programming, Part 1: Using Classes

Introduction to Graphical Applications

Flow of Control, Part 1: Selection

Flow of Control, Part 2: Looping

Object-Oriented Programming, Part 2: User-Defined Classes

Single-Dimensional Arrays

Multidimensional Arrays and the Arraylist Class

Exceptions, and Input Output Operations

Graphical User Interfaces Using Java FX

Recursion

An Introduction to Data Structures

Running Time Analysis

RGB Colors, Decimal Conversion, Java Naming, and Random Number Generation

Filters

Exam 10: Object-Oriented Programming, Part 3: Inheritance, Polymorphism, and Interfaces

Why does Java provide a protected access modifier?

An interface can contain one or more abstract methods.

Assuming that class B inherits from class A and method foo belongs to class A, what do we mean by overriding method foo in class B?

Abstract methods can be static.

When is it determined which method is called when using polymorphism?

An abstract method:

Typically, an abstract class is a class that is not completely implemented.

What keyword do we use in the class header that inherits from an interface?

To use polymorphism, the classes must be in a different hierarchy.

Inheritance is useful for which of the following?

Overriding a method and overloading a method mean the same thing.

The following code will run without errors: // Figure is an abstract class Figure f = new Figure( );

An abstract class is declared to be abstract by including the __________ keyword in the class header.

A class can implement more than one interface.

_________ allows us to use the same method call for any object in a class hierarchy.

You have written a SavingsAccount class based on the BankAccount class in the textbook. You wish to instantiate a SavingsAccount object with a starting balance of $2,175.25. Theorize why you would need to provide an overloaded constructor for the SavingsAccount class.

Public fields and methods are inherited.

The extends keyword specifies that the subclass inherits members of the superclass.

The interface concept is Java's way of implementing __________ inheritance.

When a class extends another class, the default constructor of the subclass automatically calls the default constructor of the superclass. This is called explicit invocation.

Introduction to Programming and the Java Language

Programming Building Blocks- Java Basics

Object-Oriented Programming, Part 1: Using Classes

Introduction to Graphical Applications

Flow of Control, Part 1: Selection

Flow of Control, Part 2: Looping

Object-Oriented Programming, Part 2: User-Defined Classes

Single-Dimensional Arrays

Multidimensional Arrays and the Arraylist Class

Exceptions, and Input Output Operations

Graphical User Interfaces Using Java FX

Recursion

An Introduction to Data Structures

Running Time Analysis

RGB Colors, Decimal Conversion, Java Naming, and Random Number Generation

Filters