CS 246 Howell Final
How are member functions accessed using pointers, cbv, and references?
-> (pointers) . (cbv and references)
What are the advantages of new/delete?
-New automatically allocates enough memory to hold object of specified type... no sizeof -New automatically returns a pointer to the type... no type cast needed -They can both be overloaded
Comments in C?
/* */
Comments in C++?
//
How many parameters does an overloaded unary member function have
0
How many parameters does an overloaded binary member function have
1
How many parameters does an overloaded unary friend function have
1
How many parameters does an overloaded binary friend function have
2
What library allows us to use cin and cout?
<iostream>
How does returning an object work?
A function returns a temporary object that holds the return value. The temporary copy is destroyed after the value has been returned.
What happens when the access specifier for a base class is private?
All public and protected members of the base class become private members of the derived class
What happens when the access specifier for a base class is public?
All public members of the base become public members of the derived class All protected members of the base become protected members of the derived
Overloading
An example of runtime polymorphism
What was the second method in programming
Assembly Language (1951, gibberish code)
Who invented C++
Bjarne Stroustrup in 1979 at Bell Labs in Murray Hill, New Jersey
List the disadvantage of using CBR
Call-by-reference and call-by-value code is identical
What is the GIVEN definition of an object
Data and the code to manipulate that data bound or linked together (An instance of a class)
When are copy constructors called?
During initialization (NOT assignment)
What happens when you increment an object (ob1++)?
Error unless the ++ is correctly overloaded
Who is the author of our book and what did he do?
Herbert Schildt He was on the ANSI/ISO standardization committee for C++
What was the third method in programming
High level (FORTRAN, COBOL)
What happens when we set ob1 to ob2 (ob1=ob2)
If they are of the same class, ob1 will become an exact bitwise copy of ob2.
Can derived classes inherit friend functions?
No
Can overloaded operators change precedence?
No
When we define a class is memory allocated?
No
C++ the only OO language?
No (Java, C#, etc)
What was the fifth method in programming
OOP (C++ 1989 etc)
OO, OOP, OOPL
Object Oriented, Object-Oriented Programing, Object-Oriented Programming Language
Polymorphism
One interface, multiple methods
How can we prevent damaging an object's memory?
Pass the parameter by reference Create and pass copy constructor Call by pointer
What are the three inheritance accesses
Protected, Private, Public
How are default arguments used?
So that we don't have to overload, it makes it simpler. Can go in either prototype or heading, but only in one
What was the fourth method in programming
Structural languages (Languages that include structs)
What happens when you increment a pointer to an object (p_ob1++)?
The pointer points to the next object in memory
Inheritance
The process in which one object can inherit the properties of another
List the 4 advantage(s) of using CBR
The programmer no longer needs to pass an address References offer a cleaner, more elegant interface No copy of an object is made, destructor is not called Call by references is faster than call by value
How do we use arrays of objects?
The same way as arrays of built-in types
What happens when you increment a reference?
The value of the variable is incremented (does not point to a new location)
Why do we use friend functions
To grant a non-member function access to private members.
Why do we overload operators for a class?
To increase the functionality of the class and allow it to be used in expressions
What was the first method in programming
Toggling/Switches (100101)
T/F A derived class inherit multiple base classes
True
Implenting Encapsulation
Use private and public members
When is the constructor called?
When an object comes into existence.
How does initialization happen?
When an object is created, passed, or returned to a function
Violating encapsulation
When private data members are set to public, allowing code to interfere with data
When is the deconstructor called?
When the object/function is going out of scope. They are called in reverse order after main ends.
When do we use a forward reference
When we need to use a class that does not yet exist that is already declared in another (and undefined)
C++ vs Windows programming
Windows programs are large and complex compared to C++
Do functions need to be prototyped in C++?
Yes
Can overloaded operators be inherited by derived classes?
Yes (Only the = cannot be inherited by a derived class)
Can default and non-default arguments be used?
Yes, but default arguments must have to be all the way to the right
How to use C libraries in C++?
add c in front of the library name (cstring.h instead of string.h)
What type can a data member be?
any type (programmer-defined or built-int)
How to define a class?
class class_name
How is an object created
class ob1;
What is a base class
class that defines those qualities common to all objects to be derived from the base. (Most general description)
What is a derived class
class that includes all features of the generic base class and then adds qualities specific to the derived class
How do you define a copy constructor?
class_name (const class_name &obj)
How do you define a pointer to an object?
class_name *p_ob1;
Write ob++ as an overloaded operator
classname classname :: operator++ (int notused)
How is memory allocated with new/delete malloc/free
dynamically
T/F constructors and destructors are required for classes
false
T/F friend function is a form of function overloading
false
CBR function prototype
function ( int &value )
CBP function prototype
function ( int *p_value)
CBV function heading
function ( int value)
Where do we put default arguments in program
function prototype
How to pass an object to a function using CBR (Call by reference)
function(&v)
How to pass an object to a function using CBP (Call by pointer)
function(v)
How to pass an object to a function using CBV (call by value)
function(v)
Are malloc/free operators or functions?
functions
Example of a copy constructor?
myclass (const myclass &obj)
What does ob1 - ob2 look like to the compiler?
ob1.operator - (ob2)
What does ob1 / ob2 look like to the compiler?
ob1.operator / (ob2)
What does ob1+ob2 look like to the compiler?
ob1.operator+(ob2)
Friend function parameters are usually
object(s) of the class the function is a friend of
For pointer arithmetic to work, objects must be ...
of the same type
How many classes can a function be a friend of?
one or more (no upper limit)
Are new/delete operator or functions?
operators
How to set p_ob1 to the address of ob1?
p_ob = &ob1;
what does the this* pointer point to?
points to the object that invoked a member function
Are data members public or private?
private
Are function members public or private
public
What are the two ways we can initialize an array of objects?
short hand - samp ob1[3] = {1,2,3} long hand - samp ob1[3] = {samp(1), samp(2), samp(3)}
What is the operator (::)
tells the compiler which function belongs to which class
what is encapsulation?
the mechanism that binds together code and the data it manipulates
What are the parameters of a constructor?
there is no limit
What is a copy constructor?
they are constant references, the first parameter is always a constant
What are the parameters of a destructor?
they do not have any
Do default arguments have a required order?
they go last in the declaration
How do we use friend functions when operator overloading?
to allow us to perform addition with a programmer-defined type and a built-in type
what are constructors used for?
to automatically initialize an object
T/F a constructor can be overloaded
true
What is the operator ( . )
used to invoke member functions
What is the operator (&)
used to pass by reference
What is the operator (->)
used with pointers to objects
What problem does a virtual base class solve?
virtual base classes are used to prevent multiple copies of the base class being present in an object
When can a function be on the left of an = operation?
when a function returns a reference
When do we not have to use the inline keyword?
when the function is auto-inlined
