1. State the characteristics of
procedure oriented programming.
•
Emphasis is on algorithm.
•
Large programs are divided into smaller programs called functions.
•
Functions share global data.
•
Data move openly around the system from function to function.
•
Functions transform data from one form to another.
•
Employs top-down approach in program design.
2. What are the features of Object
Oriented Programming?
•
Emphasis is on data rather than procedure.
•
Programs are divided into objects.
•
Data structures are designed such that they characterize the objects.
•
Functions that operate on the data of an object are tied together.
•
Data is hidden and cannot be accessed by external functions.
•
Objects may communicate with each other through functions.
•
New data and functions can easily be added whenever necessary.
•
Follows bottom-up approach.
3. Distinguish between Procedure
Oriented Programming and Object Oriented Programming.
Procedure Oriented Programming
|
Object Oriented Programming
|
•
Emphasis is on algorithm.
|
Emphasis
is on data rather than procedure
|
•
Large programs are divided into smaller programs called functions.
|
Programs
are divided into objects.
|
Functions
share global data.
|
Functions
that operate on the data of an object are tied together.
|
•
Data move openly around the system from function to function.
|
Data
is hidden and cannot be accessed by external functions.
|
Employs
top-down approach in program
design.
|
•
Follows bottom-up approach.
|
4. Define Object Oriented
Programming (OOP).
Object
Oriented Programming is an approach that provides a way of modularizing
programs by creating partitioned memory area for both data and functions that
can be used as templates for creating copies of such modules on
demand.
5. List out the basic concepts of
Object Oriented Programming.
•
Objects
•
Classes
•
Data Abstraction and Encapsulation
•
Inheritance
•
Polymorphism
•
Dynamic Binding
•
Message Passing
6. Define Objects.
Objects
are the basic run time entities in an object oriented system. They are instance
of a class. They may represent a person, a place etc that a program has to
handle. They may also represent user-defined data. They contain both data and
code.
7. Define Class.
Class
is a collection of objects of similar data types. Class is a user-defined data
type. The entire set of data and code of an object can be made a user defined type
through a class.
8. Define Encapsulation and Data
Hiding.
The
wrapping up of data and functions into a single unit is known as data encapsulation.
Here the data is not accessible to the outside world. The insulation of data
from direct access by the program is called data hiding or information hiding.
9. Define Data Abstraction.
Abstraction
refers to the act of representing the essential features without including the
background details or explanations.
10. Define data members and member
functions.
The
attributes in the objects are known as data members because they hold the
information. The functions that operate on these data are known as methods or
member functions.
11. State Inheritance.
Inheritance
is the process by which objects of one class acquire the properties of objects
of another class. It supports the concept of hierarchical classification and
provides the idea of reusability. The class which is inherited is known as the
base or super class and class which is newly derived is known as the derived or
sub class.
12. State Polymorphism.
Polymorphism
is an important concept of OOPs. Polymorphism means one name, multiple forms.
It is the ability of a function or operator to take more than one form at
different instances.
13. List and define the two types
of Polymorphism.
•
Operator Overloading – The process of making an operator to exhibit different
behaviors at different instances.
•
Function Overloading – Using a single function name to perform different types
of tasks. The same function name can be used to handle different number and
different types of arguments.
14. State Dynamic Binding.
Binding
refers to the linking of procedure call to the code to be executed in response
to the call. Dynamic Binding or Late Binding means that the code associated
with a given procedure call is known only at the run-time.
15. Define Message Passing.
Objects
communicate between each other by sending and receiving information known as
messages. A message to an object is a request for execution of a procedure.
Message passing involves specifying the name of the object, the name of the
function and the information to be sent.
16. List out some of the benefits of
OOP.
•
Eliminate redundant code
•
Saves development time and leads to higher productivity
•
Helps to build secure programs
•
Easy to partition work
•
Small programs can be easily upgraded to large programs
•
Software complexity can easily be managed
17. Define Object Based Programming
language.
Object
Based Programming is the style of programming that primarily supports
encapsulation and object identity. Languages that support programming with
objects are known as Object Based Programming languages.
They
do not support inheritance and dynamic binding.
18. List out the applications of
OOP.
•
Real time systems
•
Simulation and modeling
•
Object oriented databases
•
Hypertext, Hypermedia and expertext
•
AI and expert systems
•
Neural networks and parallel programming
•
Decision support and office automation systems
•
CIM/CAM/CAD systems
19. Define C++.
C++
is an object oriented programming language developed by Bjarne Stroustrup. It
is a super set of C. Initially it was known as “C with Classes”. It is a versatile
language for handling large programs.
20. What are the input and output
operators used in C++?
The
identifier cin is used for input operation. The input operator used is >>,
which is known as the extraction or get from operator. The syntax is,
cin >> n1;
The
identifier cout is used for output operation. The input operator used is <<,
which is known as the insertion or put to operator. The syntax is,
cout
<< “C++ is better than C”;
21. What is the return type of main
()?
The
return type of main () is integer i.e. main () returns an integer type value to
the operating system. Therefore, every main () should end with a return (0)
statement. It’s general format is,
int
main ()
{
…………
return
0;
}
22. List out the four basic
sections in a typical C++ program.
•
Include files
•
Class declaration
•
Member functions definition
•
Main function program
23. Define token. What are the
tokens used in C++?
The
smallest individual units in a program are known as tokens. The various tokens
in C++ are keywords, identifiers, constants, strings and operators.
24. Define identifier. What are the
rules to be followed for identifiers?
Identifiers
refer to the names of variables, functions, arrays, classes etc created by the
programmer. The rules are as follows:
•
Only alphabetic characters, digits and underscores are permitted
•
The name cannot start with a digit
•
Uppercase and lowercase letters are distinct
•
A declared keyword cannot be used as a variable name
25. State the use of void in C++.
The
two normal uses of void are
•
To specify the return type of the function when it is not returning a value
•
To indicate an empty argument list to a function
26. Define an enumeration data
type.
An
enumerated data type is a user defined data type that provides a way for attaching
names to numbers thereby increasing comprehensibility of the code. The enum
keyword is used which automatically enumerates a list of words by assigning
them values 0, 1, 2…
E.g.
enum shape {circle, square, triangle};
27. Define constant pointer and pointer
to a constant.
The
constant pointer concept does not allow us to modify the value initialized to
the pointer.
e.g.
char * const ptr = “GOOD”;
The
pointer to a constant concept doesn’t allow us to modify the address of the
pointer.
E.g.
int const * ptr = &n;
28. What are the two ways of
creating symbolic constants?
•
Using the qualifier const
•
Defining a set of integer constants using enum keyword
29. Define reference variable. Give
its syntax.
A
reference variable provides an alias or alternate name for a previously defined
variable. It must be initialized at the time of declaration. Its syntax is given
by, data-type & reference-name = variable-name;
30. List out the new operators
introduced in C++.
•
:: Scope resolution operator
•
::* Pointer to member declarator
•
->* Pointer to member operator
•
.* Pointer to member operator
•
delete Memory release operator
•
endl Line feed operator
•
new Memory allocation operator
•
setw Field width operator
31. What is the use of scope
resolution operator?
A
variable declared in an inner block cannot be accessed outside the block.
To
resolve this problem the scope resolution operator is used. It can be used to
uncover
a hidden variable. This operator allows access to the global version of
the
variable. It takes the form,
::
variable-name
32. List out the memory
differencing operator.
•
::* To declare a pointer to the member of the class
•
->* To access a member using object name and a pointer to that member
•
.* To access a member using a pointer to the object and a pointer to that
member
33. Define the 2 memory management
operators.
•
new Memory allocation operator
The
new operator can be used to create objects of any data-type. It allocates
sufficient memory to hold a data object of type data-type and returns the
address of the object.
Its
general form is,
Pointer
variable=new data-type;
•
delete Memory release operator When a data object is no longer needed it is
destroyed to release the memory space for reuse.
The
general form is,
delete
pointer variable;
34. List out the advantages of new
operator over malloc ().
•
It automatically computes the size of the data object.
•
It automatically returns the correct pointer type.
•
It is possible to initialize the objects while creating the memory space.
•
It can be overloaded.
35. Define manipulators. What are
the manipulators used in C++?
Manipulators
are operators that are used to format the data display. The manipulators used
in C++ are
•
endl – causes a linefeed to be inserted
•
setw – provides a common field width for all the numbers and forces them to be
printed right justified
36. What are the three types of
special assignment expressions?
•
Chained assignment e.g., x = y = 10;
•
Embedded assignment e.g., x = (y = 50) + 10;
•
Compound assignment e.g., x + = 10;
37. Define implicit conversion.
Whenever
data types are mixed in a expression, C++ performs the conversions
automatically. This process is known as implicit or automatic conversion.
e.g.,
m = 5 + 2.75;
38. Define integral widening
conversion.
Whenever
a char or short int appears in an expression, it is converted to an int. This
is called integral widening conversion.
39. What are the control structures
used in C++?
•
Sequence structure (straight line)
•
Selection structure (branching)
_
if – else (two way branch)
_
switch (multiple branch)
•
Loop structure (iteration or repetition)
_
do – while (exit controlled)
_
while (entry controlled)
_
for (entry controlled)
40. Define Function Prototyping.
The
function prototype describes the function interface to the compiler by giving
details such as the number and type of arguments and type of return values. It
is the declaration of a function in a program. It is in the following form,
type
function – name (argument – list);
where
argument – list -> types and names of arguments to be passed to the function
41. What is call by reference?
When
we pass arguments by reference, the formal arguments in the called function
become the aliases to the actual arguments in the calling function. Here the
function works on the original data rather than its copy.
e.g.,
void swap (int &a, int &b)
{
int
t = a;
a
= b;
b
= t;
}
42. What are inline functions?
An
inline function is a function that is expanded in line when it is invoked.
Here, the compiler replaces the function call with the corresponding function
code. The inline function is defined as,
inline
function-header
{
function
body
}
43. List out the conditions where
inline expansion doesn’t work.
•
For functions returning values, if a loop, a switch, or a goto exists
•
For functions not returning values, if a return statement exists
•
If functions contain static variables
•
If inline functions are recursive
44. Why do we use default
arguments?
The
function assigns a default value to the parameter which does not have
a
matching argument in the function call. They are useful in situations where
some
arguments always have the same value.
e.g.,
float amt (float P, float n, float r = 0.15);
45. State the advantages of default
arguments.
The
advantages of default arguments are,
•
We can use default arguments to add new parameters to the existing function.
•
Default arguments can be used to combine similar functions into one.
46. Define function overloading.
A
single function name can be used to perform different types of tasks. The same
function name can be used to handle different number and different types of
arguments. This is known as function overloading or function polymorphism.
47. List out the limitations of
function overloading.
We
should not overload unrelated functions and should reserve function overloading
for functions that perform closely related operations.
48. State the difference between
structures and class.
By
default the members of a structure are public whereas the members of a class
are private. Structure is created with the keyword struct and class is created
with the keyword class.
49. Define a class.
A
class is a way to bind the data and its function together. It allows the data
to be hidden from external use. The general form of a class is,
class
class_name
{
private:
variable
declarations;
function
declaration;
public:
variable
declarations;
function
declaration;
};
51. List the access modes used
within a class.
•
Private – The class members are private by default. The members declared private
are completely hidden from the outside world. They can be accessed from only
within the class.
•
Public – The class members declared public can be accessed from anywhere.
•
Protected – The class members declared protected can be access from within the
class and also by the friend classes.
52. How can we access the class
members?
The
class members can be accessed only when an object is created to that class.
They are accessed with the help of the object name and a dot operator. They can
be accessed using the general format,
Object_name.function_name (actual_arguments);
53. Where can we define member
functions?
Member
functions can be defined in two places:
•
Outside the class definition – The member functions can be defined outside the
class definition with the help of the scope resolution operator.
The
general format is given as,
return_type
class_name :: function_name (argument declaration)
{
function
body
}
Inside
the class definition – The member function is written inside the class in place
of the member declaration. They are treated as inline functions.
54. What are the characteristics of
member functions?
The
various characteristics of member functions are,
•
Different classes can use the same function name and their scope can be resolved
using the membership label.
•
Member functions can access the private data of a class while a nonmember function
cannot.
•
A member function can call another member function directly without using a dot
operator.
55. How can an outside function be
made inline?
An
outside function can be made inline by just using the qualifier ‘inline’ in the
header line of the function definition.
The
general format is,
inline
return_type class_name :: function_name (argument declaration)
{
function
body
}
56. What are the properties of a
static data member?
The
properties of a static data member are,
•
It is initialized to zero when the first object is created and no other initialization
is permitted.
•
Only one copy of that member is created and shared by all the objects of that
class.
•
It is visible only within the class, but the life time is the entire program.
57. What are the properties of a
static member function?
•
A static member function can access only other static members declared in the
same class.
•
It can be called using the class name instead of objects as follows,
class_name
:: function_name;
58. How can objects be used as
function arguments?
An
object can be used as a function argument in two ways,
•
A copy of the entire object is passed to the function. (Pass by value)
•
Only the address of the object is transferred to the function. (Pass by reference)
59. Define friend function?
An
outside function can be made a friend to a class using the qualifier ‘friend’.
The function declaration should be preceded by the keyword friend. A friend
function has full access rights to the private members of a class.
60. List out the special
characteristics of a friend function.
•
It is not in the scope of a class in which it is declared as friend.
•
It cannot be called using the object of that class.
•
It can be invoked without an object.
•
It cannot access the member names directly and uses the dot operator.
•
It can be declared as either public or private.
•
It has the objects as arguments.
61. Define Constructor.
A
constructor is a special member function whose task is to initialize the objects
of its class. It has the same name as the class. It gets invoked whenever an object
is created to that class. It is called so since it constructs the values of
data members of the class.
62. List some of the special
characteristics of constructor.
•
Constructors should be declared in the public section.
•
They are invoked automatically when the objects are created.
•
They do not have return types
•
They cannot be inherited.
63. Give the various types of
constructors.
There
are four types of constructors. They are
•
Default constructors – A constructor that accepts no parameters
•
Parameterized constructors – The constructors that can take arguments
•
Copy constructor – It takes a reference to an object of the same class as itself
as an argument
•
Dynamic constructors – Used to allocate memory while creating objects
64. What are the ways in which a
constructor can be called?
The
constructor can be called by two ways. They are,
•
By calling the constructor explicitly
e.g.,
integer int1 = integer (0, 100);
•
By calling the constructor implicitly
e.g.,
integer int1 (0, 100);
65. State dynamic initialization of
objects.
Class
objects can be initialized dynamically. The initial values of an object may be
provided during run time. The advantage of dynamic initialization is that
various initialization formats can be used. It provides flexibility of using different
data formats.
66. Define Destructor.
A
destructor is used to destroy the objects that have been created by a constructor.
It is a special member function whose name is same as the class and is preceded
by a tilde ‘~’ symbol.
67. Give the general form of an
operator function.
The
general form of an operator function is given as,
return-type
class-name :: operator op (arglist)
{
function
body
}
Where,
Return-type
-> type of value returned
operator
-> keyword
op
-> operator being overloaded
68. List some of the rules for
operator overloading.
•
Only existing operators can be overloaded.
•
We cannot change the basic meaning of an operator.
•
The overloaded operator must have at least one operand.
•
Overloaded operators follow the syntax rules of the original operators.
69. What are the types of type
conversions?
There
are three types of conversions. They are
•
Conversion from basic type to class type – done using constructor
•
Conversion from class type to basic type – done using a casting operator
•
Conversion from one class type to another – done using constructor or casting
operator
70. What are the conditions should
a casting operator satisfy?
The
conditions that a casting operator should satisfy are,
•
It must be a class member.
•
It must not specify a return type.
•
It must not have any arguments.
71. What are the types
of inheritance?
The various types of inheritance are,
• Single inheritance
• Multi-level inheritance
• Multiple inheritance
• Hierarchical inheritance
• Hybrid inheritance
72. Give the syntax for
inheritance.
The syntax of deriving a new class from an already existing class
is given by,
class derived-class : visibility-mode base-class
{
body of derived class
}
73. Define single
inheritance.
In single inheritance, one class is derived from an already
existing base class.
Here A is the base class and B is the derived class.
74. Define multi-level
inheritance.
n multi-level inheritance, a new class is derived from a class
already derived from the base class.Here, class B is derived from class A and
class C is further derived from the derived class B.
75. Define multiple
inheritance.
In multiple inheritance, a single class is derived from more than
one base class.
ere class C is derived from two base classes A and B.
76. Define Hierarchical
inheritance.
In hierarchical inheritance, more than one class is derived from a
single base class.
Here class B and C are derived from class A.
77. Define Hybrid
inheritance.
Hybrid inheritance is defined as a combination of more than one inheritance.
78. What is a virtual
base class?
Here, class D inherits both classes B and C which are derived from
the same base class A. Hence D has two copies of the properties of class A.
This can be avoided by declaring classes B and C as virtual base classes.
79. What is an abstract
class?
An abstract class is one that is not used to create objects. It is
designed only to act as a base class to be inherited by other classes.
80. What are the types
of polymorphism?
The two types of polymorphism are,
• Compile time polymorphism – The compiler selects the appropriate
function for a particular call at the compile time itself. It can be achieved by
function overloading and operator overloading.
• Run time Polymorphism - The compiler selects the appropriate
function for a particular call at the run time only. It can be achieved using
virtual functions.
81. Define ‘this’
pointer.
A ‘this’ pointer refers to an object that currently invokes a
member function. For e.g., the function call a. show () will set the pointer
‘this’ to the address of the object ‘a’.
82. What is a virtual
function?
When a function is declared as virtual, C++ determines which
function to use at run time based on the type of object pointed to by the base
pointer, rather than the type of the pointer.
83. What is a pure
virtual function?
A virtual function, equated to zero is called a pure virtual
function. It is a function declared in a base class that has no definition
relative to the base class.
84. How can a private
member be made inheritable?
A private member can be made inheritable by declaring the data
members as protected. When declared as protected the data members can be
inherited by the friend classes.
85.Write
some of the basic rules for virtual functions
·
Virtual functions must be member of some
class.
·
They cannot be static members and they
are accessed by using object pointers
·
Virtual function in a base class must be
defined.
·
Prototypes of base class version of a
virtual function and all the derived class versions must be identical.
·
If a virtual function is defined in the
base class, it need not be redefined in the derived class.
86.
What are pure virtual functions? Write the syntax.
A
pure virtual function is a function declared in a base class that has no
definition relative to the base class. In such cases, the compiler requires
each derived class to either define the function or redeclare it as a pure
virtual function. A class containing pure virtual functions cannot be used to
declare any object of its own. It is also known as “donothing” function.
The
“do-nothing” function is defined as follows:
virtual
void display ( ) =0;
