Question 1

Which of the following clauses allows a derived class named Truck to have the same attributes and behaviors as its base class,which is named Automobile?

Accepted Answer

The correct syntax in C# is  "class Truck : Automobile" where the colon indicates a derivation relationship. Therefore, the correct keyword is "Inherits" and the correct class name is "Automobile".

Question 2

You can create one class from another class.In OOP,this is referred to as ____.

Accepted Answer

Inheritance is the process of creating a new class from an existing class, commonly referred to as the parent or base class. The new class, often referred to as the child or derived class, inherits all the properties, methods, and behaviors of the parent class and can add or modify its own. Encapsulation, overloading, and overriding are not related to creating a new class from an existing class.

Question 3

Case 1 - chaussure.com
chaussure.com is an online shoe retailer. The applications for the web site are developed using classes and object-oriented programming techniques.
-An application needs to calculate the sales tax for an order.Which of the following is a valid example of a variable in a class that can be validated in the Set block of a Property procedure?

Accepted Answer

The correct choice is B) Private _dblTaxRate As Double. This is because encapsulation in object-oriented programming often involves using private variables within a class and providing public or protected access to them through property procedures. The use of a private variable, like _dblTaxRate, ensures that it can be validated or manipulated safely within the Set block of a Property procedure, maintaining the integrity of the data. The naming convention (prefixing with an underscore and using camelCase) is a common practice for private variables, although not strictly required by all programming languages.

Question 4

In a Property procedure,the dataType must match the data type of ____ associated with the Property procedure.

Accepted Answer

The data type of a Property procedure must match the data type of the Private variable associated with it, as the Property procedure is used to get or set the value of this Private variable.

Question 5

If you create an auto-implemented property named State,Visual Basic will create a hidden Private variable named ____.

Accepted Answer

Visual Basic convention for auto-implemented properties is to prefix the hidden Private variable with an underscore (_), so the correct option is B (_State).

Question 6

The Tree class is derived from a base class named Plant.Which of the following statements can be used by the Tree class to invoke the Plant class's default constructor?

Accepted Answer

To invoke the Plant class's default constructor, the Tree class can use the keyword "MyBase" followed by "New()" which will call the base class constructor. Therefore, the correct choice is "B) MyBase.New()".

Question 7

____ is useful when two or more methods require different parameters to perform essentially the same task.

Accepted Answer

Overloading allows developers to create multiple methods with the same name but different parameters. This is useful when multiple methods need to perform the same task but require different input parameters.

Question 8

A(n)____ is a class method whose sole purpose is to initialize the class's Private variables.

Accepted Answer

A constructor is a special type of method in a class that is used to initialize the instance variables of that class. It has the same name as the class name itself, and it is called automatically when an object of that class is created. Within the constructor, the private variables of the class can be initialized with appropriate initial values.

Question 9

Case 1 - chaussure.com
chaussure.com is an online shoe retailer. The applications for the web site are developed using classes and object-oriented programming techniques.
-Which of the following is a valid example of an object?

Accepted Answer

All options represent objects in the context of object-oriented programming as they can be instances of classes with properties and methods.

Question 10

A constructor that has no parameters is called the ____.

Accepted Answer

A constructor that has no parameters is called a default constructor. It is used to initialize an object's attributes with default values.

Question 11

When two or more methods have the same name but different parameters,the methods are referred to as ____.

Accepted Answer

When two or more methods have the same name but different parameters, they are referred to as overloaded methods. This allows the programmer to use the same method name and differentiate between them based on the types and number of parameters.

Question 12

A method name combined with its optional parameterList is called the method's ____.

Accepted Answer

The combination of a method's name and parameterList is known as the method's signature. It is used to differentiate between methods with the same name but different parameters.

Question 13

In a Property procedure,the code contained in the ____ block allows an application to retrieve the contents of the Private variable associated with the property.

Accepted Answer

The "Get" block retrieves the value of the private variable associated with the property.

Question 14

The first word in a method name should be a(n)____.

Accepted Answer

The first word in a method name should be a verb because method names are typically action-oriented and describe what the method does.

Question 15

A Property procedure begins with the keywords ____.

Accepted Answer

A Property procedure in VB.NET begins with the keywords Public [ReadOnly | WriteOnly] Property. The Public keyword indicates that the Property is accessible from outside the class, ReadOnly and WriteOnly keywords specify if the property can only be read or written to respectively.

Question 16

The code in the ____ allows an application to assign a value to the Private variable associated with the property.

Accepted Answer

The Set block is responsible for setting a value to the private variable associated with the property. The Get block retrieves the value of the private variable, the default constructor creates an instance of the object, and the Property procedure serves as the overall structure for the property.

Question 17

You indicate that a class is a derived class by including the ____ clause in the derived class's Class statement.

Accepted Answer

The "Inherits" clause is used in the derived class's Class statement to indicate that it is a derived class. This clause specifies the base class from which the derived class inherits its members. Therefore, option A is the best choice. Options B, C, and D are not relevant in this context.

Question 18

Constructors that contain parameters are called ____.

Accepted Answer

Constructors that contain parameters are called parameterized constructors. They allow objects to be initialized with specific values at the time of creation. This is useful when different objects of the same class may have different initial values or when creating objects with specific settings.

Question 19

A(n)____ property gets its value from the class itself rather than from the application.

Accepted Answer

A ReadOnly property is a property that can only have a value assigned to it during its initialization in the class constructor or field initializer. Once the value is assigned, it cannot be changed outside of the class. Therefore, the value is obtained from the class itself rather than from the application.

Question 20

The Inherits clause is the keyword ____ followed by the name of the class whose attributes and behaviors you want the derived class to inherit.

Accepted Answer

The correct keyword for specifying inheritance in C# is "Inherits". The other options mentioned are not valid keywords in C#.

Quiz 11: Classes and Objects