Deck 10: Inheritance and Polymorphism

Question 1

When you want to make sure a specific constructor from the base class is used, the derived class constructor must explicitly call the base class constructor using the ____________.

A) base keyword
B) const keyword
C) Override method
D) out parameter

Answer 1

A

Question 2

A class that is not intended to be instantiated but is to be used only as a base class is called a(n) ____________.

A) abstract class
B) dummy class
C) placeholder
D) entity class

Answer 2

A

Question 3

A(n) ____________ is a method with no body that appears in a base class, and must be overridden in a (non-abstract) derived class.

A) shadow method
B) base method
C) derived method
D) abstract method

Answer 3

D

Question 4

To override a property in the __________ you write the override keyword in the property declaration.

A) parameterized constructor
B) base class
C) field declaration
D) derived class

Question 5

The ____________ inherits fields, properties, and methods from the base class without any of them having to be rewritten.

A) super instance
B) derived class
C) initialized object
D) copy class

Question 6

A class that is not abstract is sometimes called a(n) ____________.

A) concrete class
B) base class
C) derived class
D) abstract class

Question 7

A(n) ____________ is a property that appears in a base class, and must be overridden in a (non-abstract) derived class.

A) base property
B) abstract property
C) derived property
D) public property

Question 8

The ____________ declares that a derived class is allowed to override the current method in the base class.

A) override keyword
B) class keyword
C) virtual keyword
D) static keyword

Question 9

Which one of the following is a class header indicating that we are defining a class named Amphibian, which is derived from the Animal class?

A) Amphibian : Animal
B) Animal(Amphibian)
C) Animal->Amphibian
D) Amphibian extends Animal

Question 10

Base classes are sometimes called superclasses, and derived classes are sometimes called ____________.

A) planned classes
B) copy classes
C) derivatives
D) subclasses

Question 11

In object-oriented programming, the ___________ is more general than classes related to it.

A) container class
B) default design
C) base class
D) derived class

Question 12

Which one of the following is a specialized version of a general food substance?

A) pizza
B) chocolate
C) ice cream
D) all of these

Question 13

When a derived class method has the same name as a base class method, it is often said that the derived class method ____________ the base class method.

A) shadows
B) mimics
C) overrides
D) terminates

Question 14

The ____________ declares that a method in the derived class overrides a method in the base class.

A) override keyword
B) void keyword
C) new keyword
D) virtual keyword

Question 15

When one object is a specialized version of another object, there is a(n) ____________ between them.

A) 1:1 ratio
B) "is a" relationship
C) "has a" relationship
D) shared interest

Question 16

In object oriented programming, ____________ is used to create an "is a" relationship among classes.

A) inheritance
B) progression
C) logic
D) elimination

Question 17

The term ____________ refers to an object's ability to take different forms.

A) adaptation
B) polymorphism
C) portability
D) code reuse

Question 18

To allow a property to be overridden, you must include the virtual keyword in the property's declaration in the _________ class.

A) constructor
B) derived
C) base
D) virtual

Question 19

To declare a class as abstract, you use the ____________ in the class header.

A) void keyword
B) new keyword
C) abstract keyword
D) static keyword

Question 20

A variable declared as a base class type can only be used to reference members declared in the ____________.

A) derived class
B) base class
C) abstract class
D) parameterless constructor

Question 21

In the real world you can find many objects that are specialized versions of more general objects.

Question 22

If you want to create an abstract read-only property, leave out the set accessor.

Question 23

When designing an object-oriented program, the best approach is to define a base class to hold all the general data about a group of similar objects, and then define derived classes for each specific type of object.

Question 24

You cannot assign a base class reference to a derived class variable.

Question 25

When program code instatiates a derived class object, the base class constructor executes first, followed by the derived class constructor.

Question 26

Properties in a base class can be overridden in the same way that methods can be overridden.

Question 27

A class that is not intended to be instantiated but is to be used only as a base class is called a concrete class.

Question 28

If a base class does not have a parameterless constructor, its derived class constructor must use the notation: base(parameterList) to call one of the base class's parameterized constructors.

Question 29

A method that accepts a base class variable as a parameter cannot accept a derived class variable as a parameter.

Question 30

When an "is a" relationship exists between objects, it means that the specialized object has all of the characteristics of the general object, plus additional characteristics that make it unique.

Question 31

A statement that tries to use the new operator instantiate an abstract class will not compile.

Question 32

Only methods in a derived class can directly access the base class's private members.

Question 33

You can think of a derived class as an extended version of some base class.

Question 34

If a reference to a base class object calls a method that has been overridden by a derived class, the derived class's version of the method is the one that executes.

Question 35

Inheritance involves a base class and a relative class.

Question 36

If a derived class introduces additional methods, properties, or fields, a base class reference variable cannot access them.

Question 37

New fields, properties, and methods cannot be added to a derived class unless these elements already existed in the base class.