Deck 15: Inheritance

Question 1

When the derived class gets all the member variables from the base class, we say that they are _________ from the base class.

Answer 1

inherited

Question 2

The ifstream class is derived from the __________ class.

Answer 2

istream

Question 3

A constructor of the base class is ____ inherited in the derived class is/is not)

Answer 3

is not

Question 4

If the member variables of the base class are marked as protected, who can access those variables?

Question 5

All member functions in a base class should be listed as virtual functions.

Question 6

When we derive one class from another class, this is known as ____________

Question 7

The assignment operator is inherited from the base class.

Question 8

If two functions in the same scope) have the same name, but a different function signature, this means that the functions are __________.

Question 9

A derived class automatically gets all the member variables from the base class.

Question 10

An object of a derived class can be stored in a base class variable

Question 11

The base class has everything that is in the derived class and more

Question 12

Member functions defined as private in the base class are/are not) inherited in the derived class

Question 13

The ability to associate multiple meanings to one function name using dynamic binding is called _________.

Question 14

If you use the keyword virtual in a function declaration, you must also use it in the function definition.

Question 15

The constructor for a class is inherited.

Question 16

The copy constructor from the base class is not inherited into the derived class.

Question 17

Destructors are not inherited into the derived class.

Question 18

The derived class may define variables and member functions other than those that are in the base class.

Question 19

Which is more general, the base class or the derive class.

Question 20

If the member variables in a base class are marked as private, can a derived class directly access those variables?

Question 21

In the derived class definition, you list from the base class

A) all the member functions every time
B) only those member functions that need to be redefined
C) only those member functions that were in the public section
D) only those member functions you want to overload.

Question 22

A derived class pointer can point to

Question 23

If you define a function in the derived class that has the same function signature as a function in the base class, this is known as

A) overloading
B) redefinition
C) overwriting
D) a syntax error

Question 24

If a base class has public member functions that are not listed by a derived class, then these functions

A) are not available to the derived class
B) are inherited unchanged in the derived class
C) are private to the derived class
D) do not exist in the derived class

Question 25

If a base class has declared a function to be a virtual function, then does the derived class need to include the word virtual also?

Question 26

What is another name for a child class?

A) derived class
B) sub class
C) descendent class
D) all of the above
E) none of the above

Question 27

A base class may have at most _______ child class derived from it.

A) 1
B) 2
C) 12
D) any number

Question 28

Which is the correct way to tell the compiler that the class being declared ChildClass) is derived from the base class BaseClass)?

A) class ChildClass::public BaseClass
B) class ChildClass:public BaseClass
C) class ChildClass childOf public BaseClass
D) class ChildClass derived BaseClass

Question 29

Which of the following are not true

A) an object of the derived class may be stored in a variable of the base class
B) an object of the base class may be stored in a variable of the derived class
C) an object of a derived class that is derived from another class that is derived from a third class can be stored in a variable of the third class.
D) all of the above
E) none of the above

Question 30

C++ implements polymorphism by waiting until run-time to determine which version of a function to use. This is also known as ______________.

Question 31

Using virtual functions is also known as _______ the functions

Question 32

A base class pointer variable can point to

Question 33

Give a base class with at least one public member function, how many classes can redefine that member function?

A) 1
B) 0
C) all of them
D) none of the above

Question 34

If you have the following class definitions, which of the following is the proper way to construct an object of the derived class?
Class Pet
{
Public:
Pet);
Void printPet);
String getName);
Void setNamestring newName);
Private:
String name;
};
Class Dog:public Pet
{
Public:
Dog);
Void printPet);
Void setTypestring newType);
String getType);
Private:
String type;
};

A) Dog::Dog):Pet),type"MUTT") {
}
B) Dog::Dog) {
Name="Rover";
}
C) Pet::Dog):Pet),type"MUTT") {
}
D) Dog::Pet):Pet),type"MUTT") {
}

Question 35

Which of the following are true?

A) constructors of the base class are inherited in the derived class.
B) you may not call the base constructor from the derived class
C) You must define constructors in both the base and derived classes
D) all of the above
E) none of the above

Question 36

If a base class has a public member function, and the derived class has a member function with the same name, but with a different parameter list, this function is said to be

A) overloaded
B) redefined
C) overwritten
D) a syntax error

Question 37

Using inheritance allows us to

A) eliminate duplicate code
B) make our classes more modular
C) use polymorphism
D) all of the above
E) none of the above

Question 38

When deriving a class, you should

A) list only base class functions that will be redefined
B) list all the member functions of the base class
C) make every function a virtual function
D) overload all the base class member functions

Question 39

Another name for the base class is

A) parent class
B) super class
C) ancestor class
D) all of the above
E) none of the above

Question 40

If the member variables in a base class are private, then

A) they can be directly accessed or changed in the derived class
B) the derived class must use any accesssor or modifier functions from the base class
C) making them private causes a syntax error.
D) you must declare them in the derived class also.

Question 41

If a base class has a virtual function named print, and a pointer variable of that class is pointing to a derived object, then the code ptr->print ); calls

A) the base class print function
B) the derived print function
C) both the derived and base print functions
D) it causes a run-time error

Question 42

If you have a copy constructor in the base class, but do not have a copy constructor for the derived class, then

A) you will have a syntax error
B) a copy constructor for the derived class is automatically created for you
C) you can not use pointer variables
D) the default constructor is used

Question 43

If a base class has a non-virtual member function named print, and a pointer variable of that class is pointing to a derived object, then the code ptr->print ); calls

A) the base class print function
B) the derived print function
C) both the derived and base print functions
D) it causes a run-time error

Question 44

If a derived class Class2) has redefined a function from the base class Class 1), how can that derived function call the base class function if the function declaration is as follows?
Void print );

A) :public Class1::print );
B) Class1 :: print );
C) print );
D) all of the above.

Question 45

Given the following classes and code, what is the output of the last statement shown?
Class Pet
{
Public:
Virtual void print);
String name;
Private:
};
Class Dog: public Pet
{
Public:
Void print);
String breed;
};
Void Pet::print)
{
Cout << "My name is " << name;
}
Void Dog::print)
{
Pet::print);
Cout << ", and my breed is a "<< breed << endl;
}
Pet* pPtr;
Dog* dPtr=new Dog;
DPtr->name= "Rover";
DPtr->breed="Weiner";
PPtr= dPtr;
PPtr->print);

A) My name is Rover, and my breed is a Weiner
B) My name is Rover
C) , and my breed is a Weiner
D) nothing

Question 46

Given the following classes and code, what is the output of the last statement shown?
Class Pet
{
Public:
Virtual void print);
String name;
Private:
};
Class Dog: public Pet
{
Public:
Void print);
String breed;
};
Void Pet::print)
{
Cout << "My name is " << name;
}
Void Dog::print)
{
Pet::print);
Cout << ", and my breed is a "<< breed << endl;
}
Pet pPtr;
Dog dPtr;
DPtr->name= "Rover";
DPtr->breed="Weiner";
PPtr= dPtr;
PPtr->print);

A) My name is Rover, and my breed is a Weiner
B) My name is Rover
C) , and my breed is a Weiner
D) nothing

Question 47

Given a class A that derives from a class B that derives from a class C, when an object of class A goes out of scope, in which order are the destructors called?

A) C, B, then A
B) A, B, then C
C) unable to determine
D) depends on how the code is written for the destructors

Question 48

Which of the following would correctly call the base class BaseClass) assignment operator from the derived class DerivedClass) assignment operator?
DerivedClass& DerivedClass::operator =const DerivedClass& rightSide)
{
//what goes here?
}

A) BaseClass::operator=rightSide);
B) leftSide=rightSide;
C) rightSide=BaseClass.rightSide;
D) DerivedClass::rightSide=BaseClass::rightSide;

Question 49

Which of the following should be virtual if a base class uses dynamic memory allocation?

A) the constructor
B) the copy constructor
C) the print function
D) the destructor

Question 50

In order to tell the compiler to wait to decide which version of a function to use, you must precede the function declaration in the base class with the keyword

A) operator
B) friend
C) virtual
D) void

Question 51

You should make a function a virtual function if

A) every class that is derived from this class use all the member functions from this class.
B) every class that is derived from this class needs to re-define this function.
C) that function is an operator
D) only in the derived classes

Question 52

Polymorphism refers to

A) the ability to assign multiple meanings to one function name.
B) overriding base class functions.
C) overloading functions
D) none of the above

Question 53

Given the following simplified classes,
Class Pet
{
Public:
Virtual void print);
String name;
Private:
};
Class Dog: public Pet
{
Public:
Void print);
String breed;
};
Dog vDog;
Pet vPet;
VDog.name="rover";
VDog.breed = "Collie";
Which of the following statements are not legal?

A) vPet=vDog; cout << vDog.name;
B) vPet=vDog; cout << vDog.breed;
C) vPet=vDog; cout << vPet.name;
D) vPet=vDog; cout << vPet.breed;