Deck 10: Classes and Data Abstraction

Question 1

In C++ terminology, a class object is the same as a class instance.

Answer 1

True

Question 2

The public members of a class must be declared before the private members.

Answer 2

False

Question 3

A ____ sign in front of a member name on a UML diagram indicates that this member is a public member.

A) +
B) -
C) #
D) $

Answer 3

A

Question 4

If an object is declared in the definition of a member function of the class, then the object can access both the public and private members of the class.

Question 5

class rectangleType
{
public:
void setLengthWidth(double x, double y);
//Postcondition: length = x; width = y;
void print() const;
//Output length and width;
double area();
//Calculate and return the area of the rectangle;
double perimeter();
//Calculate and return the parameter;
rectangleType();
//Postcondition: length = 0; width = 0;
rectangleType(double x, double y);
//Postcondition: length = x; width = y;
private:
double length;
double width;
};
Consider the accompanying class definition in Figure 2. Which of the following variable declarations is correct?

A) rectangle rectangleType;
B) class rectangleType rectangle;
C) rectangleType rectangle;
D) rectangle rectangleType.area;

Question 6

A ____ sign in front of a member name on a UML diagram indicates that this member is a protected member.

A) +
B) -
C) #
D) $

Question 7

You can use arithmetic operators to perform arithmetic operations on class objects.

Question 8

Consider the UML class diagram shown in the accompanying figure. According to the UML class diagram, how many private members are in the class?

A) none
B) zero
C) two
D) three

Question 9

Given the declaration
class myClass
{
public:
void print(); //Output the value of x;
MyClass();
private:
int x;
};
myClass myObject;
The following statement is legal.
myObject.x = 10;

Question 10

If a member of a class is ____, you cannot access it outside the class.

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

Question 11

A class is an example of a structured data type.

Question 12

Which of the following class definitions is correct in C++?

A) class studentType
{
Public:
Void setData(string, double, int);
Private:
String name;
};
B) class studentType
{
Public:
Void setData(string, double, int);
Void print() const;
Private:
String name;
Double gpa;
}
C) class studentType
{
Public void setData(string, double, int);
Private string name;
};
D) studentType class
{
Public: void setData(string, double, int);
Private: string name;
};

Question 13

If an object is created in a user program, then the object can access both the public and private members of the class.

Question 14

In C++, class is a reserved word and it defines only a data type.

Question 15

As parameters to a function, class objects can be passed by reference only.

Question 16

The word ____ at the end of the member functions in the accompanying class clockType in Figure 1 specifies that these functions cannot modify the member variables of a clockType object.

A) static
B) const
C) automatic
D) private

Question 17

Consider the UML class diagram shown in the accompanying figure. Which of the following is the name of the class?

A) clock
B) clockType
C) Type
D) +clockType

Question 18

The components of a class are called the ____ of the class.

A) elements
B) members
C) objects
D) properties

Question 19

A class and its members can be described graphically using a notation known as the ____ notation.

A) OON
B) OOD
C) UML
D) OOP

Question 20

If the heading of a member function of a class ends with the word const, then the function member cannot modify the private member variables, but it can modify the public member variables.

Question 21

A class object can be ____. That is, it can be created once, when the control reaches its declaration, and destroyed when the program terminates.

A) static
B) automatic
C) local
D) public

Question 22

class rectangleType
{
public:
void setLengthWidth(double x, double y);
//Postcondition: length = x; width = y;
void print() const;
//Output length and width;
double area();
//Calculate and return the area of the rectangle;
double perimeter();
//Calculate and return the parameter;
rectangleType();
//Postcondition: length = 0; width = 0;
rectangleType(double x, double y);
//Postcondition: length = x; width = y;
private:
double length;
double width;
};
Consider the accompanying class definition, and the object declaration: rectangleType bigRect(14,10);
Which of the following statements is correct?

A) bigRect.setLengthWidth();
B) bigRect.setLengthWidth(3.0, 2.0);
C) bigRect.length = 2.0;
D) bigRect.length = bigRect.width;

Question 23

If a function of a class is static, it is declared in the class definition using the keyword static in its ____.

A) return type
B) parameters
C) heading
D) main function

Question 24

A member function of a class that only accesses the value(s) of the data member(s) is called a(n) ____ function.

A) accessor
B) mutator
C) constructor
D) destructor

Question 25

How many destructors can a class have?

A) no explicit destructors
B) one
C) two
D) any number

Question 26

In C++, the scope resolution operator is ____.

A) :
B) ::
C) $
D) .

Question 27

Which of the following is true about classes and structs?

A) By default, all members of a struct are public and all members of a class are private.
B) A struct variable is passed by value only, and a class variable is passed by reference only.
C) An assignment operator is allowed on class variables, but not on struct variables.
D) You cannot use the member access specifier private in a struct.

Question 28

To guarantee that the member variables of a class are initialized, you use ____.

A) accessors
B) mutators
C) constructors
D) destructor

Question 29

By default, all members of a class are ____________________.

Question 30

In C++, the ____ is an operator called the member access operator.

A) .
B) ,
C) ::
D) #

Question 31

Non-static member variables of a class are called the ____________________ variables of the class.

Question 32

In C++, you can pass a variable by reference and still prevent the function from changing its value by using the keyword ____ in the formal parameter declaration.

A) automatic
B) private
C) static
D) const

Question 33

class rectangleType
{
public:
void setLengthWidth(double x, double y);
//Postcondition: length = x; width = y;
void print() const;
//Output length and width;
double area();
//Calculate and return the area of the rectangle;
double perimeter();
//Calculate and return the parameter;
rectangleType();
//Postcondition: length = 0; width = 0;
rectangleType(double x, double y);
//Postcondition: length = x; width = y;
private:
double length;
double width;
};
Consider the accompanying class definition, and the declaration: rectangleType bigRect;
Which of the following statements is correct?

A) rectangleType.print();
B) rectangl
C) bigRect.print();
D) bigRect::print();

Question 34

A class object can be ____. That is, it is created each time the control reaches its declaration, and destroyed when the control exits the surrounding block.

A) static
B) automatic
C) local
D) public

Question 35

What does ADT stand for?

A) abstract definition type
B) asynchronous data transfer
C) abstract data type
D) alternative definition type

Question 36

A destructor has the character ____, followed by the name of the class.

A) .
B) ::
C) #
D) ~

Question 37

A constructor with no parameters is called the ____________________ constructor.

Question 38

A(n) ____________________ function of a class changes the values of the member variable(s) of the class.

Question 39

If a class object is passed by ____________________, the contents of the member variables of the actual parameter are copied into the corresponding member variables of the formal parameter.

Question 40

A program or software that uses and manipulates the objects of a class is called a(n) ____________________ of that class.

Question 41

A C++ implementation file has the extension ____________________.

Question 42

The header file is also known as the ____________________.

Question 43

Classes were specifically designed in C++ to handle ____________________.

Question 44

A(n) ____________________ is a statement specifying what is true after the function call is completed.

Question 45

To create the object code file for any source code file, the command line option ____________________ is used on the system command line.

Question 46

A(n) ____________________ statement is required by any program that uses a header class file, as well as by the implementation file that defines the operations for that class.

Question 47

Object code is produced from a(n) ____________________.

Question 48

A(n) ____________________ is a statement specifying the condition(s) that must be true before the function is called.

Question 49

A(n) ____________________ contains the definitions of the functions to implement the operations of an object.