Classes

Question 1

Header

Answer 1

Text file defining class and implementation

Question 2

Client code needs to know what about a class?

Answer 2

Member functions
Arguments for member functions
Return type of member functions

Question 3

Interfaces

Answer 3

Define how things interact with eachother

Question 4

What consists of a class’s interface?

Answer 4

Public member functions

Question 5

How do you separate a class’s interface from it’s implementation?

Answer 5

Class definition in header and member functions defined in source code file

Question 6

Function prototypes

Answer 6

Describe class’s public interface without revealing implementation

Question 7

Why does class header specify class’s private data members?

Answer 7

Compiler must know how much data to reserve for each object of the class

Question 8

Class header

Answer 8

Provides compiler with info to ensure class’s member functions are called correctly

Question 9

What is an include guard?

Answer 9

ifndef, #define, #endif

Prevents header from being included multiple times

Question 10

Scope resolution operator

Answer 10

::

Tells compiler that the member function is within that class’s scope/definition

Question 11

Why include class header in source code file?

Answer 11

Ensures member function matches prototype and member functions know class data members and functions

Question 12

What exception can a function throw?

Answer 12

invalid_argument

Question 13

What is a throw statement?

Answer 13

Creates and throws an object of the type specified

Question 14

What happens after exception object is created?

Answer 14

throw statement immediately terminates the function and the exception is returned to the calling function

Question 15

What are objects of ostringstream?

Answer 15

Same functionality as cout but writes their output to string objects in memory

Question 16

ostringstream’s str member function does what?

Answer 16

Returns the string created

Question 17

Stream manipulator setfill

Answer 17

Specifies fill character when integer is output in field wider than number of digits in value

Question 18

Sticky setting

Answer 18

Applies to all subsequent values displayed, ex: setfill

Question 19

What is a member function defined in a class’s body?

Answer 19

Implicitly declared inline

Question 20

Defined classes can be used as types in declarations of…

Answer 20

Objects, references, and pointers

Question 21

Member functions are stored __________ from the objects of the class

Answer 21

Separately

Question 22

What belongs to a class’s scope?

Answer 22

Data members and member functions

Question 23

Nonmember functions are defined at what scope?

Answer 23

Global namespace

Question 24

Within class’s scope, class members are accessible to….

Answer 24

Member non-static functions

Question 25

Outside of class scope, class members are referenced through....

Answer 25

An object name, a reference to an object, or a pointer to an object

Question 26

What has block-scope?

Answer 26

Variables declared in a member function

Question 27

Dot member selection operator (.)

Answer 27

Accesses the object's, or reference to an object's, public members

Question 28

Arrow member selection operator (->)

Answer 28

Used with pointer to access object's public members

Question 29

Access functions

Answer 29

Read or display data Also test truth/falsity (called predicate functions)

Question 30

Utility functions

Answer 30

Private member function that enables use of public member functions. Not intended for use by clients

Question 31

How do you overload?

Answer 31

Provide prototypes and constructors for each overloaded version

Question 32

How can a constructor call other constructors in the same class and what is it called?

Answer 32

Use a member initializer with the name of the class Called a delegating constructor

Question 33

Destructor

Answer 33

Called implicitly when an object is destroyed Uses ~

Question 34

Destructor's termination housekeeping

Answer 34

Before system can reclaim an object's memory, it's reused to hold new objects

Question 35

How many destructors does each class have?

Answer 35

1, if not explicitly, compiler creates empty destructor

Question 36

What order are destructor calls made?

Answer 36

Reverse of constructor calls Global and local static destructors are called after all non-static local objects are destroyed

Question 37

What is function exit?

Answer 37

Terminates program immediately after fatal unrecoverable error occurs Does not execute destructors

Question 38

What is function abort?

Answer 38

Terminates program immediately Does not allow any programmer-defined cleanup Indicates abnormal termination

Question 39

What are references?

Answer 39

Alias for name of object Acceptable lvalue and can receive a value

Question 40

When can a reference not be used as a modifiable lvalue?

Answer 40

If the function returns a reference to const data

Question 41

What is memberwise assignment?

Answer 41

= used to assign an object to another object of the same type

Question 42

Objects can be passed by value or returned by value from functions. How?

Answer 42

Copy constructor creates new object and copies original values in

Question 43

const keyword

Answer 43

Object is not modifiable

Question 44

non-const member calls on const member objects

Answer 44

Compiler does not allow

Question 45

const member function attempt to modify object

Answer 45

Compilation error

Question 46

Where is member function declared const?

Answer 46

Prototype and definition

Question 47

const objects must be ________.

Answer 47

Initialized

Question 48

What cannot be declared const?

Answer 48

Constructors and destructors

Question 49

What is composition?

Answer 49

Class can have objects of other classes as members

Question 50

When are member objects constructed in enclosing class objects?

Answer 50

Before

Question 51

Friend functions

Answer 51

Can access all the class's members. Defined outside class's scope.

Question 52

Where is friend declaration allowed?

Answer 52

Anywhere in the class

Question 53

Is friend relationship symmetric or transitive?

Answer 53

Neither

Question 54

this pointer

Answer 54

Object can access its own address Not part of object itself

Question 55

this pointer is passed as an implicit argument to each ______________

Answer 55

Non-static member function

Question 56

This pointer can be called explicitly to reference

Answer 56

Data members and member functions

Question 57

Cascaded-member-function calls

Answer 57

When multiple functions are invoked in the same statement. Enabled by this pointer.

Question 58

Static data members

Answer 58

Class-scope Can be public, private, or protected

Question 59

How to access public static class member when no object exists?

Answer 59

Prefix classname with name of data member and scope resolution operator

Question 60

Static can be applied to definition outside of class definition? T or F

Answer 60

True

Question 61

When should a member function be declared static?

Answer 61

If it does not access non-static members