Question 1

Usually, an abstract class contains at least one abstract method.

Accepted Answer

A) True 
 B)False

Question 2

When class B inherits from class A:

Accepted Answer

A)   A is the superclass and B is the subclass.
B)   A is the subclass and B is the superclass.C) A) and B)
D) undefined

Question 3

Abstract methods can be overridden.

Accepted Answer

A) True 
 B)False

Question 4

Which of the following cannot be an interface member?

Accepted Answer

A)   A class
B)   A constant
C)   A mutator method
D)   An abstract methodE) B) and C)
F) A) and D)

Question 5

Several classes implement an interface, but all of them implement the same method using the same code. To provide a common method for all of these classes, you would create an abstract class.

Accepted Answer

A) True 
 B)False

Question 6

Private fields and methods are part of the inheriting class object.

Accepted Answer

A) True 
 B)False

Question 7

Which of the options listed will happen if the following code segment is run, assuming the remainder of the program is coded correctly?
10 public class Circle extends Figure
11 {
12 private int radius;
13 public Circle( ) 
14 {
15 super( ) ;
16 radius = 0;

Accepted Answer

A)   The default constructor of the Figure class will be called (line 15) .
B)   The default constructor of Radius class will set radius to 0.
C)   The attempt to instantiate an object of the abstract class will generate a compiler error.
D)   All of these are correct.E) B) and D)
F) A) and C)

Question 8

If the call to the direct superclass constructor was not the first statement in the constructor, a compiler error will be generated.

Accepted Answer

A) True 
 B)False

Question 9

A method in a subclass overriding a method in a superclass cannot call the superclass method.

Accepted Answer

A) True 
 B)False

Question 10

Suppose you write a program in which you attempt to use a subclass to directly access a private password field in a superclass. Predict what will happen, and suggest a solution that would result in a different outcome.

Accepted Answer

An attempt by a subclass to directly acc...

Question 11

Protected fields and methods are inherited.

Accepted Answer

A) True 
 B)False

Question 12

If a class has an abstract method, then that class must be declared abstract.

Accepted Answer

A) True 
 B)False

Question 13

The extends keyword specifies that the subclass inherits members of the superclass, so:

Accepted Answer

A)   the base class begins with a set of predefined methods and fields inherited from its hierarchy of superclasses.
B)   the derived class begins with a set of predefined methods and fields inherited from its hierarchy of superclasses.
C)   the derived class begins with a set of predefined methods inherited from its hierarchy of fields.
D)   the base class begins with a set of predefined methods inherited from its hierarchy of derived classes.E) B) and C)
F) None of the above

Question 14

Which of the following is true of polymorphism?

Accepted Answer

A)   It simplifies the processing of various elements in the same class hierarchy.
B)   To use polymorphism, the classes must be in a different hierarchy.
C)   In Greek, the term means "many changes."
D)   All of these are correct.E) A) and C)
F) A) and D)

Question 15

Some OOP developers call a subclass the base class and call a superclass the derived class.

Accepted Answer

A) True 
 B)False

Question 16

Which Java keyword do we use in the constructor of a class inheriting from another class if we want to call the constructor of the inherited class?

Accepted Answer

A)   call
B)   super
C)   constructor
D)   cloneE) B) and C)
F) A) and D)

Question 17

An interface can contain one or more static constants.

Accepted Answer

A) True 
 B)False

Question 18

Which of the following are not inherited by subclasses?

Accepted Answer

A)   public fields and public methods
B)   private fields and private methods
C)   protected fields and protected methods
D)   All of these are correct.E) A) and D)
F) A) and C)

Question 19

Inheritance helps organize related classes into __________.

Accepted Answer

The answer of Inheritance helps organize related classes into __________....

Question 20

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

Accepted Answer

A) True 
 B)False

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

A method in a subclass overriding a method in a superclass cannot call the superclass method.

Correct AnswerverifiedShow Answer

Several classes implement an interface, but all of them implement the same method using the same code. To provide a common method for all of these classes, you would create an abstract class.

Correct AnswerverifiedShow Answer

The extends keyword specifies that the subclass inherits members of the superclass, so:

Correct AnswerverifiedShow Answer

An interface can contain one or more static constants.

Correct AnswerverifiedShow Answer

Which of the following are not inherited by subclasses?

Correct AnswerverifiedShow Answer

Protected fields and methods are inherited.

Correct AnswerverifiedShow Answer

Abstract methods can be overridden.

Correct AnswerverifiedShow Answer

If the call to the direct superclass constructor was not the first statement in the constructor, a compiler error will be generated.

Correct AnswerverifiedShow Answer

If a class has an abstract method, then that class must be declared abstract.

Correct AnswerverifiedShow Answer

Which of the options listed will happen if the following code segment is run, assuming the remainder of the program is coded correctly? 10 public class Circle extends Figure 11 { 12 private int radius; 13 public Circle( ) 14 { 15 super( ) ; 16 radius = 0;

Correct AnswerverifiedShow Answer

Inheritance helps organize related classes into __________.

Correct AnswerverifiedShow Answer

When class B inherits from class A:

Correct AnswerverifiedShow Answer

Which Java keyword do we use in the constructor of a class inheriting from another class if we want to call the constructor of the inherited class?

Correct AnswerverifiedShow Answer

Which of the following cannot be an interface member?

Correct AnswerverifiedShow Answer

Usually, an abstract class contains at least one abstract method.

Correct AnswerverifiedShow Answer

Which of the following is true of polymorphism?

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

Suppose you write a program in which you attempt to use a subclass to directly access a private password field in a superclass. Predict what will happen, and suggest a solution that would result in a different outcome.

Correct AnswerverifiedAn attempt by a subclass to directly acc...View AnswerShow Answer

Private fields and methods are part of the inheriting class object.

Correct AnswerverifiedShow Answer

Some OOP developers call a subclass the base class and call a superclass the derived class.

Correct AnswerverifiedShow Answer

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An attempt by a subclass to directly acc...
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