Question 1

All methods in an abstract class are inherently abstract.

Accepted Answer

A) True 
 B)False

Question 2

Concrete classes provide implementations for every method and property they define.

Accepted Answer

A) True 
 B)False

Question 3

Which of the following does not complete the sentence correctly
An interface.

Accepted Answer

A)  forces classes that implement it to declare all the interface methods. 
B)  is used in place of an abstract class when there is no default implementation to inherit. 
C)  cannot be instantiated. 
D)  can be instantiated. 
A)  forces classes that implement it to declare all the interface methods. 
B)  is used in place of an abstract class when there is no default implementation to inherit. 
C)  cannot be instantiated. 
D)  can be instantiated.

Question 4

A concrete class that implements an interface must define all methods and properties of that interface.

Accepted Answer

A) True 
 B)False

Question 5

Which of the following statements about abstract base classes is true

Accepted Answer

A)  abstract base classes may contain data. 
B)  abstract base classes may not contain implementations of methods. 
C)  abstract base classes must declare all methods as abstract. 
D)  abstract base classes must declare all data members not given values as abstract. 
A)  abstract base classes may contain data. 
B)  abstract base classes may not contain implementations of methods. 
C)  abstract base classes must declare all methods as abstract. 
D)  abstract base classes must declare all data members not given values as abstract.

Question 6

All methods in a sealed class must be explicitly declared sealed.

Accepted Answer

A) True 
 B)False

Question 7

________ code is the process by which the compiler replaces method calls with the code of a method to improve performance.

Accepted Answer

A)  Debugging 
B)  Inlining 
C)  Compiling 
D)  None of the above. 
A)  Debugging 
B)  Inlining 
C)  Compiling 
D)  None of the above.

Question 8

A(n)________ is best used for providing services that bring together objects of otherwise unrelated classes.

Accepted Answer

A)  abstract class 
B)  concrete class 
C)  interface 
D)  None of the above. 
A)  abstract class 
B)  concrete class 
C)  interface 
D)  None of the above.

Question 9

The purpose of an interface is to:

Accepted Answer

A)  provide similar objects with the same functionality, even though each will imple 
B)  provide different types of objects with the comparable functionality, even though each will imple 
C)  provide default implementations of methods and properties 
D)  None of the above. 
A)  provide similar objects with the same functionality, even though each will imple 
B)  provide different types of objects with the comparable functionality, even though each will imple 
C)  provide default implementations of methods and properties 
D)  None of the above.

Question 10

An abstract class may be derived from another abstract class.

Accepted Answer

A) True 
 B)False

Question 11

Polymorphism involves:

Accepted Answer

A)  the same message sent to a variety of objects, which each interpret their own way 
B)  a specific message sent to each specific object 
C)  different messages sent to one object 
D)  None of the above. 
A)  the same message sent to a variety of objects, which each interpret their own way 
B)  a specific message sent to each specific object 
C)  different messages sent to one object 
D)  None of the above.

Question 12

Sealing methods allows the compiler to optimize the program by "inlining code."

Accepted Answer

A) True 
 B)False

Question 13

Abstract classes may not be:

Accepted Answer

A)  inherited 
B)  accessed by derived-classes 
C)  instantiated 
D)  None of the above. 
A)  inherited 
B)  accessed by derived-classes 
C)  instantiated 
D)  None of the above.

Question 14

If an app needs to perform a derived-class-specific operation on a derived class object reference by a base class variable,the app must first cast the base class reference to a derived class reference through a technique known as _________.

Accepted Answer

A)  downcasting 
B)  upcasting 
C)  decreasecasting 
D)  increasecasting 
A)  downcasting 
B)  upcasting 
C)  decreasecasting 
D)  increasecasting

Question 15

An abstract base class can be used to declare references.

Accepted Answer

A) True 
 B)False

Question 16

Operator is returns true if two matching types are being compared.

Accepted Answer

A) True 
 B)False

Question 17

Declaring a method sealed means:

Accepted Answer

A)  it will prepare the object for garbage collection 
B)  it cannot be accessed from outside its class 
C)  it cannot be overloaded 
D)  it cannot be overridden 
A)  it will prepare the object for garbage collection 
B)  it cannot be accessed from outside its class 
C)  it cannot be overloaded 
D)  it cannot be overridden

Question 18

Objects of abstract base classes can be instantiated.

Accepted Answer

A) True 
 B)False

Question 19

An interface is typically used in place of an abstract class when there is no default implementation to inherit.

Accepted Answer

A) True 
 B)False

Question 20

An interface can not provide properties with get and set accessors.

Accepted Answer

A) True 
 B)False

Exam 12: Object-Oriented Programming: Polymorphism

All methods in an abstract class are inherently abstract.

Concrete classes provide implementations for every method and property they define.

Which of the following does not complete the sentence correctly An interface.

A concrete class that implements an interface must define all methods and properties of that interface.

Which of the following statements about abstract base classes is true

All methods in a sealed class must be explicitly declared sealed.

________ code is the process by which the compiler replaces method calls with the code of a method to improve performance.

A(n)________ is best used for providing services that bring together objects of otherwise unrelated classes.

The purpose of an interface is to:

An abstract class may be derived from another abstract class.

Polymorphism involves:

Sealing methods allows the compiler to optimize the program by "inlining code."

Abstract classes may not be:

If an app needs to perform a derived-class-specific operation on a derived class object reference by a base class variable,the app must first cast the base class reference to a derived class reference through a technique known as _________.

An abstract base class can be used to declare references.

Operator is returns true if two matching types are being compared.

Declaring a method sealed means:

Objects of abstract base classes can be instantiated.

An interface is typically used in place of an abstract class when there is no default implementation to inherit.

An interface can not provide properties with get and set accessors.

Introduction to Computers, the Internet and Visual C#

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Introduction to C# Apps

Introduction to Classes,Objects,Methods and Strings

Control Statements: Part 1

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Methods: a Deeper Look

Arrays;Introduction to Exception Handling

Introduction to Linq and Generic Collections

Classes and Objects: A Deeper Look

Object-Oriented Programming: Inheritance

Exception Handling: A Deeper Look

GUI With Windows Forms: Part 1

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