Deck 4: Inheritance and Class Hierarchies

Question 1

The objects of a derived class __________ the original data fields and members of a base class.

Answer 1

inherit

Question 2

Classes can be arranged in a hierarchy, with a top-level __________ class.

Answer 2

base

Question 3

Objects further down the hierarchy are more complex and less general than those further up.

Answer 3

True

Question 4

The __________ relationship between classes means that every instance of one class is or may be associated with one or more instances of the other class (but not necessarily the other way around).

Question 5

A Ford Model-T automobile is in a "has-a" relationship with __________.

A) automobiles
B) antique automobiles
C) a Rolls Royce Silver Ghost
D) an engine

Question 6

According to the inheritance structure defined by the code fragment below, an Airplane is a kind of Jet_Plane.
class Jet_Plane : public Airplane {
private:
int num_engines;
Jet_Engine jets[4];
// ...
};

Question 7

If the execution of any constructor in a derived class does not invoke a base class constructor, C++ automatically invokes the no-parameter constructor for the __________ class.

A) sub
B) base
C) child
D) subordinate

Question 8

In general, it is better to use __________ visibility, because derived classes may be written by different programmers, and it is always a good practice to restrict and control access to the base-class data fields.

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

Question 9

Member functions generally have __________ visibility, so we should be able to access a member function that is inherited.

Question 10

Having multiple member functions with the same name but different signatures in a class is called member function __________.

Question 11

Suppose two Clock class functions named get_military_time use the following headers:
Std::string get_military_time (int hours, int minutes);
Std::string get_military_time (int hours, int minutes, int seconds);
The get_military__time member function is said to be __________.

A) overloaded
B) overridden
C) downcast
D) extended

Question 12

If a member function is declared __________, then when it is called through a pointer (or reference) variable the actual member function will be determined at run time and based on the type of the object pointed to (or referenced).

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

Question 13

The C++ compiler can assign object addresses to pointers at program run-time.

Question 14

A(n) __________ function is a virtual function that is declared but for which no body (definition) is provided.

Question 15

Which of the following statements is a valid abstract member function declaration for class Food?

A) abstract double percent_protein();
B) abstract double percent_protein() const = 0;
C) virtual double percent_protein();
D) virtual double percent_protein() const = 0;

Question 16

A pointer variable (l-value) that is of type pointer-to- __________ class may point to a derived object (r-value).

A) sub
B) child
C) base
D) derived

Question 17

Given that the Lap_Top class derives from Computer class, which of the following pointer declarations is legal?

A) Lap_Top* a_laptop = new Computer( ... );
B) Computer* a_computer = new Lap_Top( ... );
C) Lap_Top* a_laptop = Computer( ... );
D) *a_computer = new LapTop( ... );

Question 18

If you dynamically cast a pointer to a lower type object, the lower type object is promoted to a higher type.

Question 19

Complete the header for class Artist, which inherits from both class Musician and class Writer.
class Artist __________

Question 20

__________ is a process that resolves name conflicts by collecting common data fields and member functions into a common base class.

A) Overloading
B) Refactoring
C) Overriding
D) Casting

Question 21

__________ are used to group collections of declarations into a functional unit.

Question 22

At the top of the level of the namespace hierarchy resides the global namespace, whose name is effectively the __________ string.

Question 23

The statement __________ creates an object of type stack as defined in the optimize namespace.
Class stack { ... }; // Defined in the global namespace
Namespace optimize {
Class stack { ... }; // Defined in the optimize namespace
}

A) stack aStack;
B) std::stack aStack;
C) optimize aStack;
D) optimize::stack aStack;

Question 24

To access a single name from the namespace in which it was declared requires a using __________ .

Question 25

Private visibility is for members of a class that should not be accessible to anyone but the class, not even classes that extend it.