Question 1

Classes can have a "has a" relationship. This is a concept called ____ or aggregation.
A) "is a"
B) inheritance
C) polymorphism
D) containment

Accepted Answer

The "has a" relationship is also known as containment or aggregation. It means that one class contains an instance of another class as a member variable. In this relationship, the contained class is a part of the containing class but can also exist on its own. This is different from inheritance, where the subclass is a type of the superclass (answer B), and polymorphism (answer C), which involves using multiple classes with a shared interface. Therefore, the best choice is D - containment.

Question 2

Components are implemented in C# through ____.
A) classes
B) encapsulation
C) namespaces
D) packages

Accepted Answer

Components in C# are typically implemented using classes, as classes provide a way to encapsulate related data and behavior. Encapsulation is important for creating modular, reusable code, which is a key aspect of component-based development. Namespaces and packages are also important concepts in C#, but they do not directly correspond to the implementation of components.

Question 3

By defining data members as private, you protect the data and enable access only through the object's methods and properties. This describes the ____ feature.
A) abstraction
B) encapsulation
C) polymorphism
D) inheritance

Accepted Answer

Encapsulation is the feature that describes defining data members as private, protecting the data, and enabling access only through the object's methods and properties. Abstraction is another feature of OOP that enables you to create simplified and generalized interfaces. Polymorphism refers to the ability of an object to take on many forms, while inheritance is a mechanism for creating new classes by deriving them from existing ones.

Question 4

Software components often take the form of classes or collections of methods.

Accepted Answer

The answer of Software components often take the form of...

Question 5

Enabling multiple implementations of the same behaviors so that the appropriate implementation can be executed based on the situation describes ____ as it relates to object oriented development.
A) abstraction
B) encapsulation
C) polymorphism
D) inheritance

Accepted Answer

Polymorphism is the concept that allows different objects to be treated as if they were the same type, enabling multiple implementations of the same behaviors so that the appropriate one can be executed based on the situation. This is typically achieved through the use of inheritance and interfaces in object-oriented programming. Abstraction is the process of hiding unnecessary details, encapsulation is the idea of combining data and methods in a single unit to protect data from being manipulated unintentionally, and inheritance is the mechanism of basing an object or class upon another object or class, retaining similar implementation.

Question 6

In addition to creating the console and Windows applications you've already created, you can create class library files with a dynamic link library (.EXE) extension that can be reused.

Accepted Answer

Class library files are created with a dynamic link library (.DLL) extension, not an .EXE extension. .EXE files are executable files, while .DLL files contain code that can be reused by different programs.

Question 7

The ____ keyword can be used to spread the definition of your classes over multiple files.
A) base
B) partial
C) class
D) interface

Accepted Answer

The partial keyword can be used to split the definition of a class over multiple files. This can be useful in situations where a class is large and complex, or when multiple developers are working on different parts of the same class.

Question 8

The Unified Modeling Language (UML) notation for the interfaces specifies that the name of the Interface methods should appear in italics.

Accepted Answer

According to the UML notation, the names of Interface methods should appear in italics.

Question 9

Multiple classes can implement the same interface, but a class can implement only one interface.

Accepted Answer

A class can implement multiple interfaces, allowing for more flexible design and code reuse.

Question 10

Through defining the methods of a class as private, you protect the class.

Accepted Answer

The answer of Through defining the methods of a class...

Question 11

Object-oriented development focuses on designing classes that can be reused. One way to ensure this reuse is through designing and building components that can be stored in a library and called on when needed.

Accepted Answer

Object-oriented development emphasizes design and implementation of reusable classes and building components that can be saved in a library for later use, promoting code reuse and reducing development time.

Question 12

Abstraction provides a way to simplify complex problems by generalizing and then representing only essential features appropriate to the problem.

Accepted Answer

Abstraction involves identifying the essential features of a problem and representing them in a simplified manner, which can help to tackle complex problems more effectively.

Question 13

You have experienced the use of polymorphism in programs through the use of the Main( ) method.

Accepted Answer

The use of polymorphism in programs is not limited to Main( ) method, it can be seen throughout the code where objects of different classes can be treated as objects of a common superclass or interface.

Question 14

Packaging data attributes and behaviors into a single unit so that implementation details can be hidden describes ____ as it relates to object oriented development.
A) abstraction
B) encapsulation
C) polymorphism
D) inheritance

Accepted Answer

Encapsulation is the technique of packaging related data attributes and behaviors into a single unit (class) and providing access to only the necessary parts of the object, hiding implementation details from other parts of the code. This promotes code modularity, reusability, and maintainability.

Question 15

Which access modifier should be used to give derived classes direct access to change the parent member data. This access modifier does not allow classes that instantiate objects of the class to have access to change member data?
A) private
B) public
C) protected
D) internal

Accepted Answer

The protected access modifier allows derived classes to directly access and modify the parent member data, but it does not allow other classes that instantiate objects of the class to have access to change member data. This is a good choice for situations where we want to provide some level of access to subclass but still want to restrict direct access to the member data from other classes. Private access modifier restricts access to the member data only to the class in which it is defined. Public access modifier makes the member data accessible to all classes in the program, while internal access modifier allows access from classes in the same assembly.

Question 16

Enabling reuse of code through extending the functionality of classes describes ____ as it relates to object oriented development.
A) abstraction
B) encapsulation
C) polymorphism
D) inheritance

Accepted Answer

Inheritance allows for code reuse and extension of functionality through the creation of a new class that inherits the properties and methods of an existing class. The new class can then add or modify those properties and methods to suit its specific needs, while still maintaining the original functionality of the parent class.

Question 17

Class library files end with a(n) ____ extension.
A) .class
B) .dll
C) .exe
D) .cs

Accepted Answer

Class library files in Windows generally have the .dll extension, which stands for Dynamic Link Library. A .dll file contains compiled code that can be used by multiple applications. The other options (.class, .exe, and .cs) are file extensions used for different types of files in programming, but not specifically for class libraries in Windows.

Question 18

Constructors are defined with ____ access modifiers.
A) private
B) public
C) protected
D) internal

Accepted Answer

Constructors should be defined with a public access modifier to allow objects to be created from the class by other parts of the program.

Question 19

To override a method, the base method may include any of the following keywords, EXCEPT ____.
A) virtual
B) abstract
C) interface
D) override

Accepted Answer

The keyword "interface" is not related to overriding methods. The other three keywords (virtual, abstract, override) are all relevant to overriding methods.

Question 20

Replacing a method defined at a higher level creates a(n) ____.
A) overloaded method
B) overridden method
C) virtual method
D) abstract method

Accepted Answer

When a method defined in a superclass is redefined in a subclass with the same name and signature, it is called method overriding. The behavior of the overridden method is replaced by the subclass's version of the method.

Quiz 11: Advanced Object-Oriented Programming Features

Classes can have a "has a" relationship. This is a concept called ____ or aggregation.

Components are implemented in C# through ____.

By defining data members as private, you protect the data and enable access only through the object's methods and properties. This describes the ____ feature.

Software components often take the form of classes or collections of methods.

Enabling multiple implementations of the same behaviors so that the appropriate implementation can be executed based on the situation describes ____ as it relates to object oriented development.

In addition to creating the console and Windows applications you've already created, you can create class library files with a dynamic link library (.EXE) extension that can be reused.

The ____ keyword can be used to spread the definition of your classes over multiple files.

The Unified Modeling Language (UML) notation for the interfaces specifies that the name of the Interface methods should appear in italics.

Multiple classes can implement the same interface, but a class can implement only one interface.

Through defining the methods of a class as private, you protect the class.

Object-oriented development focuses on designing classes that can be reused. One way to ensure this reuse is through designing and building components that can be stored in a library and called on when needed.

Abstraction provides a way to simplify complex problems by generalizing and then representing only essential features appropriate to the problem.

You have experienced the use of polymorphism in programs through the use of the Main( ) method.

Packaging data attributes and behaviors into a single unit so that implementation details can be hidden describes ____ as it relates to object oriented development.

Which access modifier should be used to give derived classes direct access to change the parent member data. This access modifier does not allow classes that instantiate objects of the class to have access to change member data?

Enabling reuse of code through extending the functionality of classes describes ____ as it relates to object oriented development.

Class library files end with a(n) ____ extension.

Constructors are defined with ____ access modifiers.

To override a method, the base method may include any of the following keywords, EXCEPT ____.

Replacing a method defined at a higher level creates a(n) ____.