Deck 9: Using Classes and Objects

Question 1

The ____ class access modifier means that access is limited to another class to which the class belongs.

A) private
B) internal
C) protected
D) public

Answer 1

A

Question 2

Instance variables are often called ____ to help distinguish them from other variables you might use.

A) states
B) relationships
C) instantiations
D) fields

Answer 2

D

Question 3

The ____ class access modifier means that access is limited to the assembly (a group of code modules compiled together) to which the class belongs.

A) private
B) internal
C) protected
D) public

Answer 3

B

Question 4

When you create an array of objects, the array holds the actual value of each of the objects.

Question 5

The ____ class access modifier means that access to the class is not limited.

A) protected
B) private
C) internal
D) public

Question 6

The data components of a class that differ for each object are stored in ____.

A) instance variables
B) states
C) instantiations
D) relationships

Question 7

A(n) ____ parameter is one that is undeclared and that gets its value automatically.

A) implicit
B) explicit
C) instance
D) property

Question 8

If you do not provide an access specifier for a class field, its access is ____ by default.

A) public
B) internal
C) private
D) protected

Question 9

Properties have ____ that specify the statements that execute when a class's fields are accessed.

A) instance variables
B) fields
C) operators
D) accessors

Question 10

A class that instantiates objects of another prewritten class is known as a class client or class ____.

A) state
B) instantiation
C) user
D) server

Question 11

Using private fields within classes is an example of ____, a feature found in all object-oriented languages.

A) information hiding
B) polymorphism
C) inheritance
D) overloading

Question 12

Only nonstatic methods receive a this reference.

Question 13

Predefined types such as int , double , and char are ____ types.

A) reference
B) value
C) output
D) pointer

Question 14

A(n) ____ constructor will never take any parameters.

A) object
B) default
C) initializer
D) array

Question 15

The ____ class access modifier means that access to the class is limited to the class and to any classes derived from the class.

A) internal
B) private
C) protected
D) public

Question 16

The set of contents of an object's instance variables also is known as its ____.

A) relationship
B) state
C) instantiation
D) field

Question 17

An implicit, or invisible, ____ reference is passed to every instance method and property accessor.

A) static
B) object
C) use
D) this

Question 18

If you don't write a constructor for a class object, C# writes one for you.

Question 19

You can overload an operator for a built-in data type. For example, you can change the meaning of + between two int s.

Question 20

A GUI object, such as a Button , is represented as an object that cannot encapsulate any methods.

Question 21

What is the difference between overriding a method and overloading a method with respect to method signatures?

Question 22

The Sort() method accepts an array as a parameter and arranges its elements in descending order. What complication arises when you sort an array of objects? Explain how to use the IComparable interface to address this problem.

Question 23

As an alternative to repeating code in multiple constructors, a ____ indicates that another instance of a class constructor should be executed before any statements in the current constructor body.

A) parameterless constructor
B) value constructor
C) constructor initializer
D) default constructor

Question 24

When a method ____ another, it takes precedence over the method, hiding the original version.

A) instantiates
B) overrides
C) overloads
D) extends

Question 25

Briefly explain how to create instance variables, and show how to define a private integer instance variable called idNumber within a class called Employee .

Question 26

Classes that support simple data items each contain a method named ____, which provides the details of how items in the class compare to each other.

A) Equals()
B) Less()
C) IndexOf()
D) CompareTo()

Question 27

What are the three parts of a class definition in C#?

Question 28

Like any other C# method, constructors can be overloaded. Show how to create two public constructors-one with no parameters, and one with a parameter called sal -that both set the value for the property Salary within the following class:
class Employee
{
public double Salary;
}

Question 29

What are the class access modifiers in C#?

Question 30

A(n) ____ is a collection of abstract methods (and perhaps other members) that can be used by any class, as long as the class overrides the abstract method definitions.

A) multifile assembly
B) framework
C) interface
D) destructor

Question 31

Methods associated with objects are called ____________________.

Question 32

A ____ contains the actions you require when an instance of a class is destroyed-for example, when the instance goes out of scope.

A) constructor
B) constructor initializer
C) destructor
D) parameterless constructor

Question 33

Briefly describe what an object initializer does and give a specific example. When is the object initializer assignment made?

Question 34

A(n) ____________________ is a member of a class that provides access to a field of a class.

Question 35

Properties contain ____________________ for setting an object's fields.

Question 36

Creating an object requires two steps that are shown in the example below:
Employee myAssistant;
myAssistant = new Employee();
What do these statements accomplish?

Question 37

C# contains a(n) ____ interface, which contains the definition for the CompareTo() method that compares one object to another and returns an integer.

A) IComparable
B) Comparable
C) ICompareTo
D) CompareTo

Question 38

An object is a(n) ____________________ (tangible example) of a class.

Question 39

Write an example method that overrides the + operator to create a new book whose title is a concatenation of the titles of two books. For example, if the first book's title is "The Adventures of Tom Sawyer" and the second book's title is "The Adventures of Huckleberry Finn", the concatenated title will be "The Adventures of Tom Sawyer and The Adventures of Huckleberry Finn".  Assume the book class is defined as:
class Book
{
public Book( string title)
{
Title = title;
}
public string Title {get; set;}
}

Question 40

A(n) ____________________ is a method that instantiates (creates an instance of) an object.

Question 42

Explain what a destructor is and why it cannot be overloaded.