Question 1

When deriving a class from a protected base class, the public members of the base class become _________ and the protected members of the base class become __________?
A) protected, private
B) public, private
C) protected, protected
D) public, protected

Accepted Answer

When deriving a class from a protected base class, the public members of the base class become protected in the derived class, and the protected members of the base class remain protected in the derived class.

Question 2

Base class constructors and assignment operators:
A) Are not inherited by derived classes.
B) Should not be called by derived class constructors and assignment operators.
C) Can be inherited by derived classes, but generally are not.
D) Can call derived-class constructors and assignment operators.

Accepted Answer

Base class constructors and assignment operators are not inherited by derived classes. However, they can be accessed and called by the derived class constructors and assignment operators using the scope resolution operator. It is not recommended to call them directly in the derived class constructors and assignment operators as it may result in undefined behavior.

Question 3

Public CommissionEmployee
Which of the following is false?
A) The colon : ) in the header of the class definition indicates inheritance.
B) The keyword public indicates the type of inheritance.
C) All the public and protected members of class BasePlusCommissionEmployee are inherited as public and protected members, respectively, into class CommissionEmployee.
D) CommissionEmployee is the base class and BasePlusCommissionEmployee is the derived class.

Accepted Answer

In the given context, CommissionEmployee is the derived class, not the base class, so it cannot inherit members from BasePlusCommissionEmployee.

Question 4

CommissionEmployee first, last, ssn, sales, rate )
The second line:
A) Invokes the CommissionEmployee constructor with arguments.
B) Causes a compiler error.
C) Is unnecessary because the CommissionEmployee constructor is called automatically.
D) Indicates inheritance.

Accepted Answer

The second line invokes the CommissionEmployee constructor with arguments, providing values for the parameters first, last, ssn, sales, and rate. This creates a new CommissionEmployee object with the specified data.

Question 5

The is-a relationship represents.
A) Composition.
B) Inheritance.
C) Information Hiding.
D) A friend.

Accepted Answer

The is-a relationship represents inheritance, where a subclass inherits properties and behaviors from its superclass.

Question 6

Which of the following is not a kind of inheritance in C++?
A) public.
B) private.
C) static.
D) protected.

Accepted Answer

The three types of inheritance in C++ are public, private, and protected. Static is not a type of inheritance, it is a keyword used to define class-level variables and functions.

Question 7

Protected base class members cannot be accessed by:
A) Functions that are neither friends of the base class, derived-class member functions nor friends of a derived class.
B) friends of the base class.
C) Functions that are not derived-class member functions.
D) friends of derived classes.

Accepted Answer

Protected members can only be accessed by the members and friends of the base class and derived classes. Option A correctly identifies that functions that are neither friends of the base class, derived-class member functions nor friends of a derived class cannot access protected members.

Question 8

From most restrictive to least restrictive, the access modifiers are:
A) protected, private, public
B) private, protected, public
C) private, public, protected
D) protected, public, private

Accepted Answer

Access modifiers determine the accessibility of classes, methods, and other members in object-oriented programming.

Private members are accessible only within the same class, whereas protected members are accessible within the same class and its subclasses. Public members are accessible by any code that can access the class.

Therefore, the correct order of access modifiers in terms of restrictiveness, arranged from most restrictive to least restrictive, is: private, protected, public.

Therefore, the correct choice is B, as it has the correct order.

Question 9

Suppose class A inherits from base class B. What is the order in which their constructors and destructors will be called when an object of class A is instantiated and then destroyed?
A) B constructor, A constructor, A destructor, B destructor.
B) B constructor, A constructor, B destructor, A destructor.
C) A constructor, B constructor, A destructor, B destructor.
D) A constructor, B constructor, B destructor, A destructor.

Accepted Answer

When an object of a derived class is created, the base class constructor is called first, followed by the derived class constructor. When the object is destroyed, the derived class destructor is called first, followed by the base class destructor.

Question 10

Which of the following is not a good example of a hierarchy likely to be modeled by inheritance?
A) Airplanes.
B) Geometric shapes.
C) Animals.
D) Prime numbers.

Accepted Answer

Prime numbers do not have a clear hierarchy that can be modeled by inheritance. Inheritance is better suited for hierarchical relationships, such as between different types of animals or different types of geometric shapes. Airplanes could potentially be modeled by inheritance, depending on the specific hierarchy being considered.

Question 11

When should base class members be declared protected?
A) When all clients should be able to access these members.
B) When these members are used only by member functions of this base class.
C) When these members should be available only to derived classes and friends), but not to other clients.
D) The protected access specified should never be used.

Accepted Answer

Protected access is used to make members available to derived classes and friends, but not to other clients. This is useful for implementing inheritance and enforcing encapsulation. If all clients should be able to access the members, they should be declared public. If the members are used only by member functions of the base class, they can be declared private. The protected access specified is a valid and useful tool when used appropriately.

Question 12

Which forms of inheritance are is-a relationships?
A) All forms of inheritance are is-a relationships.
B) Only public and private.
C) Only public and protected.
D) Only public.

Accepted Answer

The answer of Which forms of inheritance are is-a relationships?
A)...

Question 13

Which of the following is true about using inheritance in software engineering?
A) Common attributes and behaviors should be factored out of closely related classes and placed into a base class from which the original classes can now inherit.
B) It is best to create a huge class library to make it easy for a client to find the most appropriate class for his or her needs.
C) A class produced through inheritance should be as large as possible to fully encompass all of the functionality it should offer.
D) The standard C++ libraries that are shipped with C++ compilers are usually enough to accomplish anything an application might need to do.

Accepted Answer

Inheritance is used to avoid duplicate code by allowing closely related classes to share common attributes and behaviors. This is achieved by creating a base class that contains these common attributes and behaviors, and then having the other classes inherit from it. This helps to simplify the code and make it easier to read and maintain.

B, C, and D are incorrect choices because they are not true in regards to using inheritance. Creating a huge class library can actually make it more difficult for a client to find the appropriate class they need, and creating a class that is too large can make it difficult to understand and maintain. Additionally, while the standard C++ libraries are useful, they may not always provide all the functionality an application requires.

Question 14

Which of the following is not one of the disadvantages of using the "copy-and-paste" approach to duplicating code from one class into another class?
A) Errors are prone to be spread around.
B) It is time consuming.
C) It forces the system to store many physical copies of the code, creating a code-maintenance nightmare.
D) All of the above are disadvantages of the "copy-and-paste" approach.

Accepted Answer

The answer of Which of the following is not one...

Question 15

When an object of a derived class is instantiated, the __________ constructor initializes the _________ members.
A) Base class, base class.
B) Derived class, base class.
C) Base class, derived class.
D) Derived class, public.

Accepted Answer

The base class constructor initializes the base class members when an object of a derived class is instantiated. This ensures that the inherited attributes are properly set up before the derived class's own constructor potentially modifies them or adds additional functionality.

Question 16

Which of the following is most likely a base class of the other three?
A) automobile.
B) convertible.
C) miniVan.
D) sedan.

Accepted Answer

An automobile is a generic term for any motorized vehicle with four wheels that is designed for transportation on roads. A convertible, a miniVan, and a sedan are all types of automobiles, but they are more specific and have additional features beyond just being a basic motorized vehicle. Therefore, it is logical to assume that "automobile" is the base class from which the other three types of vehicles are derived.

Question 17

Select the false statement regarding inheritance.
A) A derived class can contain more attributes and behaviors than its base class.
B) A derived class can be the base class for other derived classes.
C) Some derived classes can have multiple base classes.
D) Base classes are usually more specific than derived classes.

Accepted Answer

This statement is false because base classes are usually more general or abstract than derived classes, as they provide a foundation for the derived classes to build upon.

Question 18

To declare class subClass a privately derived class of superClass one would write:
A) class subclass : private superClass
B) class subclass :: private superClass
C) class subclass < private superClass >
D) class subclass inherits private superClass

Accepted Answer

The correct syntax for declaring a privately derived class is to use the keyword "private" followed by the name of the base class. The correct syntax for this is "class subclass : private superClass". Option B is incorrect because "::" is used to access members of a namespace or class. Option C is incorrect because the "<" and ">" symbols are used for templates, not inheritance. Option D is incorrect because "inherits" is not a keyword in C++.

Question 19

Theoretically, clients do not need to see the _________ of classes from which they derive other classes.
A) Header files.
B) Source code.
C) Object code.
D) Interface.

Accepted Answer

Clients do not need to see the source code of classes from which they derive other classes, as they only need to interact with the interface or API provided.

Quiz 12: Object-Oriented Programming: Inheritance

When deriving a class from a protected base class, the public members of the base class become _ and the protected members of the base class become __?

Base class constructors and assignment operators:

Public CommissionEmployee Which of the following is false?

CommissionEmployee first, last, ssn, sales, rate ) The second line:

The is-a relationship represents.

Which of the following is not a kind of inheritance in C++?

Protected base class members cannot be accessed by:

From most restrictive to least restrictive, the access modifiers are:

Suppose class A inherits from base class B. What is the order in which their constructors and destructors will be called when an object of class A is instantiated and then destroyed?

Which of the following is not a good example of a hierarchy likely to be modeled by inheritance?

When should base class members be declared protected?

Which forms of inheritance are is-a relationships?

Which of the following is true about using inheritance in software engineering?

Which of the following is not one of the disadvantages of using the "copy-and-paste" approach to duplicating code from one class into another class?

When an object of a derived class is instantiated, the __ constructor initializes the _ members.

Which of the following is most likely a base class of the other three?

Select the false statement regarding inheritance.

To declare class subClass a privately derived class of superClass one would write:

Theoretically, clients do not need to see the _________ of classes from which they derive other classes.