Deck 11: Inheritance and Composition

Question 1

The class io is the base class of the C++ stream classes istream and ostream.

Answer 1

False

Question 2

If inheritance is private, all members of the base class, including private members, become private members of the derived class.

Answer 2

False

Question 3

____ is a "has-a" relationship.

A) Inheritance
B) Encapsulation
C) Composition
D) Polymorphism

Answer 3

C

Question 4

Existing classes, from which you create new classes, are called ____ classes.

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

Question 5

Suppose that bClass is a class. Which of the following statements correctly derives the class dClass from bClass?

A) class dClass:: public bClass
{
//classMembersList
};
B) class dClass: private bClass
{
//classMembersList
};
C) class dClass:: protected bClass
{
//classMembersList
};
D) class bClass: public dClass
{
//classMembersList
};

Question 6

The new classes that we create from existing classes are called ____ classes.

A) sibling
B) base
C) derived
D) parent

Question 7

A derived class can directly access the protected members of the base class.

Question 8

In protected inheritance, public and protected members of the base class become the protected members of the derived class.

Question 9

The constructors of a derived class can (directly) initialize only the (public data) members inherited from the base class of the derived class.

Question 10

The private members of a base class can be directly accessed by a derived class.

Question 11

Classes can create new classes from existing classes. This important feature ____.

A) encourages code reuse
B) aids the separation of data and operations
C) provides public access to the internal state of an object
D) results in more software complexity

Question 12

If the derived class does not override a public member function of the base class, you may specify a call to that public member function by using the name of the function and the appropriate parameter list.

Question 13

Consider the following class definition: class dClass: bClass
{
//class members list
};
The class dClass is derived from the class bClass using the ____ type of inheritance.

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

Question 14

In multiple inheritance, the derived class has more than one base class.

Question 15

A call to the base class's constructor is specified in the heading of the definition of a derived class constructor.

Question 16

A derived class cannot directly access public members of a base class.

Question 17

Which of the following is true about inheritance?

A) All public member functions of the base class become the public member functions of the derived class.
B) All public member variables of the base class become the public member variables of the derived class.
C) All public members of the base class become the public members of the derived class.
D) The public member variables of the base class become the public or private member variables of the derived class.

Question 18

Inheritance is an example of a(n) ____ relationship.

A) is-a
B) has-a
C) handshaking
D) had-a

Question 19

Which of the following is a valid definition of the derived class bClass?

A) class aClass: public bClass
{
//)..
};
B) class bClass: public aClass
{
//)..
};
C) class aClass::bClass
{
//)..
};
D) class bClass::aClass
{
//)..
}

Question 20

Which of the following class definitions makes the public members of the class aClass become the public members of the class bClass?

A) class aClass: public bClass
{
//)..
};
B) class bClass: public aClass
{
//)..
};
C) class bClass: aClass
{
//)..
};
D) class aClass: bClass
{
//)..
};

Question 21

Which of the following is true about a derived class?

A) A derived class can directly access any member variable of the base class.
B) A derived class can redefine any public member function of the base class.
C) A derived class can have at most one base class.
D) A derived class can redefine any member function of the base class.

Question 22

To ____ a public member function of a base class in the derived class, the corresponding function in the derived class must have the same name, number, and types of parameters.

A) redefine
B) overload
C) rename
D) reuse

Question 23

____ is the ability to use the same expression to denote different operations.

A) Inheritance
B) Encapsulation
C) Polymorphism
D) Composition

Question 24

If inheritance is public, all protected members of the base class are ____________________ members of the derived class.

Question 25

The ____ members of an object form its external state.

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

Question 26

C++ provides ____ functions as a means to implement polymorphism in an inheritance hierarchy, which allows the run-time selection of appropriate member functions.

A) redefined
B) overridden
C) virtual
D) overloaded

Question 27

Which of the following statements about inheritance is true if memberAccessSpecifier is protected?

A) The private members of the base class become protected members of the derived class.
B) The derived class can directly access any member of the base class.
C) The public members of the base class become protected members of the derived class.
D) The protected members of the base class become private members of the derived class.

Question 28

If the derived class classD overrides a public member function functionName of the base class classB, then to specify a call to that public member function of the base class you use the statement ____.

A) classD::functionName();
B) classB::functionName();
C) classD.functionName();
D) classB.functionName();

Question 29

The preprocessor directive ____________________ is used to prevent multiple inclusions of a header file in a program.

Question 30

____ is the ability to combine data, and operations on that data, in a single unit.

A) Inheritance
B) Encapsulation
C) Polymorphism
D) Composition

Question 31

Consider the following class definitions: class bClass
{
Public:
Void set(double a, double b);
//Postcondition: x = a; y = b;
Void print() const;
BClass();
//Postcondition: x = 0; y = 0;
BClass(double a, double b);
//Postcondition: x = a; y = b;
Private:
Double x;
Double y;
};
Class dClass: public bClass
{
Public:
Void set(double a, double b, double c);
//Postcondition: x = a; y = b; z = c;
Void print() const;
DClass();
//Postcondition: x = 0; y = 0; z = 0 ;
DClass(double a, double b, double c);
//Postcondition: x = a; y = b; z = c;
Private:
Double z;
};
Which of the following dClass constructor definitions is valid in C++?

A) dClass::dClass(double a, double b, double c)
: bClass()
{
X = a;
Y = b;
Z = c;
}
B) dClass::dClass(double a, double c)
{
X = a;
Z = c;
}
C) dClass::dClass(double a, double b)
: bClass()
{
X = a;
Y = b;
}
D) dClass::dClass(double a, double b, double c)
: bClass(a, b)
{
Z = c;
}

Question 32

OOP implements ____.

A) UML
B) IPE
C) EIP
D) OOD

Question 33

If the corresponding functions in the base class and the derived class have the same name but different sets of parameters, then this function is ____ in the derived class.

A) reused
B) redefined
C) overloaded
D) overridden

Question 34

What is the output of the following program? #include
Using namespace std;
Class bClass
{
Public:
Void print() const;
BClass(int a = 0, int b = 0);
//Postcondition: x = a; y = b;
Private:
Int x;
Int y;
};
Class dClass: public bClass
{
Public:
Void print() const;
DClass(int a = 0, int b = 0, int c = 0);
//Postcondition: x = a; y = b; z = c;
Private:
Int z;
};
Int main()
{
BClass bObject(2, 3);
DClass dObject(3, 5, 8);
BObject.print();
Cout << endl;
DObject.print();
Cout << endl;
Return 0 ;
}
Void bClass::print() const
{
Cout << x << " " << y << endl;
}
BClass::bClass(int a, int b)
{
X = a;
Y = b;
}
Void dClass::print() const
{
BClass:print();
Cout << " " << z << endl;
}
DClass::dClass(int a, int b, int c)
: bClass(a, b)
{
Z = c;
}

A) 2 3
2 3
B) 2 3
3 5 8
C) 3 5 8
3 5 8
D) 5 8
3 5 8

Question 35

The ____ members of an object form its internal state.

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

Question 36

In ____________________, the derived class is derived from a single base class.

Question 37

Consider the following class definitions: class bClass
{
Public:
Void setX(int a);
//Postcondition: x = a;
Void print() const;
Private:
Int x;
};
Class dClass: public bClass
{
Public:
Void setXY(int a, int b);
//Postcondition: x = a; y = b;
Void print() const;
Private:
Int y;
};
Which of the following correctly sets the values of x and y?

A) void dClass::setXY(int a, int b)
{
BClass::setX(a);
Y = b;
}
B) void dClass::setXY(int a, int b)
{
X = a;
Y = b;
}
C) void dClass::setXY(int a, int b)
{
X = bClass::setX(a);
Y = bClass::setY(b);
}
D) void dClass::setXY(int a, int b)
{
X = bClass.setX(a);
B = y;
}

Question 38

To define new classes in C++, you create new ____________________ files.

Question 39

The constructor of a derived class cannot directly access the ____________________ member variables of the base class.

Question 40

Consider the following class definitions: class bClass
{
Public:
Void setX(int);
Void print() const;
Private:
Int x;
};
Class dClass: public bClass
{
Public:
Void setXY(int, int);
Void print() const;
Private:
Int y;
};
Which of the following statements correctly redefines the member function print of bClass?

A) void dClass::print() const
{
DClass:print();
Cout << " " << y << endl;
}
B) void dClass::print() const
{
Cout << x << " " << y << endl;
}
C) void bClass::print() const
{
Cout << x << " " << y << endl;
}
D) void dClass::print() const
{
BClass::print();
Cout << "y = " << y << endl;
}

Question 41

The term ____________________ is used to describe the ability to create new objects from existing objects.

Question 42

In the case of composition, the ____________________ name is used to invoke the constructor.

Question 43

In object-oriented design, we debug ____________________; in structured programming, we debug functions.

Question 44

In ____________________ (aggregation), one or more members of a class are objects of another class type.

Question 45

C++ provides ____________________ functions as a means to implement polymorphism in an inheritance hierarchy.

Question 46

In ____________________ polymorphism, the (data) type is left unspecified and then later instantiated.

Question 47

Objects are created when ____________________ variables are declared.

Question 48

The OOP terminology is influenced by the vocabulary of ____________________, the OOP language largely developed at a Xerox research center during the 1970s.

Question 49

In OOD, a program is a collection of interacting ____________________; in structured programming, a program is a collection of interacting functions.

Question 50

In C++, we implement ADT through the use of ____________________.