CS2203 OBJECT ORIENTED PROGRAMMING QUESTION BANKS

CS2203 OBJECT ORIENTED PROGRAMMING

OOPS,CS2203 OBJECT ORIENTED PROGRAMMING QUESTION BANKS, anna university question bank for CSE, Anna University, QUESTION BANKS, VIVA-QUESTIONS, 

TWO MARK QUESTION AND ANSWER 

UNIT I

1. Give some characteristics of procedure-oriented language.
   
   

1. Emphasis is on doing things (algorithms).
2. Larger programs are divided into smaller programs known as functions.
3. Most of the functions share global data.
4. Data move openly around the system from function to function.
5. Employs top-down approach in program design.

Function-1

Function-2

Function-3
Function-4

Function-5
Main program

2. Write any four features of OOPS.
   The features of OOPS are,

      1. Emphasis is on data rather than on procedure.
      2. Programs are divided into objects.
      3. Data is hidden and cannot be accessed by external functions.
      4. Follows bottom -up approach in program design.

3. What are the basic concepts of OOPS?
   the basic concepts of OOPS are,

1.    Objects.

2.    Classes.

3.    Data abstraction and Encapsulation.

4.    Inheritance.

5.    Polymorphism.

6.    Dynamic binding.

7.    Message passing.

4. What is object?
   
   

Objects are basic run-time entities in an object-oriented system. They may represent a person, a place, a bank account, a table of data or any item that the program has to handle. Each object has the data and code to manipulate the data and theses objects interact with each other.

5. What is class?
   
   

1.      Collection of objects of similar type.

2.      Once a class has been defined, we can create any number of objects belonging to the classes.

3.      Classes are user-defined data types and behave like built-in types of the programming language.

6. What is encapsulation?
   
   
1. Wrapping up of data and function within the structure is called as encapsulation.
2. The insulation of data from direct access by the program is called as data hiding or information binding.
3. The data is not accessible to the outside world and only those functions, which are wrapped in the class, can access it.
   
   
7. What are data members and member functions?
   
   

Classes use the concept of abstraction. They are defined as a list of abstract attributes such as size, weight, and cost and uses functions to operate on these attributes.
The attributes are sometimes called as data members because they hold information. The functions that operate on these data are called as member functions or methods.
Eg: int a, b; // a, b are data members
Void getdata ( ); // member function

8.  What is dynamic binding or late binding?
   
   

Dynamic binding means that the code associated with a given procedure    

call is not known until the time of the call at the run-time.

9.  Write the process of programming in an object-oriented language?
   
   
1. Create classes that define objects and their behavior.
2. Creating objects from class definition.
3. Establishing communication among objects.
   
   

10.  Give any four advantages of OOPS.
    The  advantages of OOPS are,

1.       The principle of data hiding helps the programmer to build secure programs that cannot be invaded by code in other parts of the program.

2.       It is possible to have multiple instances of an object to co-exist without any interference.

3.       Object oriented programming can be easily upgraded from small to large systems.

4.       Software complexity can be easily managed.

11.  What are the features required for object-based programming Language?
    The features required for object-based programming are,

1.       Data encapsulation.

2.       Data hiding and access mechanisms.

3.       Automatic initialization and clear up of objects.

4.       Operator overloading.

12.  Give any four applications of OOPS.
    The applications of OOPS are,

1.       Real-time systems.

2.       Simulation and modeling.

3.       Object-oriented databases.

4.       AI and expert systems.

13.  What are tokens?
    The smallest individual units in a program are known as tokens. C++ has the following tokens,

     1. Keyword

     2. Identifiers

     3. Constants

     4. Strings

     5. Operator

14.  What are keywords?
    
    

The keywords implement specific C++ language features. They are explicitly reserved identifiers and cannot be used as names fro the program variables or other user defined program elements.
Eg: go to, If, struct, else, union etc.

15.  Rules for naming the identifiers in C++.
    
    

1. Only alphabetic characters, digits and underscore are permitted.
2. The name cannot start with a digit.
3. The upper case and lower case letters are distinct.
4. A declared keyword cannot be used as a variable name.

16.  What are the operators available in C++?
    
    

All operators in C are also used in C++. In addition to insertion operator << and extraction operator >> the other new operators in C++ are,

:: 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

17.  What is a scope resolution operator?
    
    

Scope resolution operator is used to uncover the hidden variables. It also allows access to global version of variables.

Eg:
#include<iostream. h>
int m=10; // global variable m
void main ( )
{
int m=20; // local variable m
cout<<”m=”<<m<<”\n”;
cout<<”: : m=”<<: : m<<”\n”;
}
output:
20
10 (: : m access global m)
Scope resolution operator is used to define the function outside the class.
Syntax:
Return type <class name> : : <function name>
Eg:
Void x : : getdata()

18. What is a default argument?
    
    

Default arguments assign a default value to the parameter, which does not have matching argument in the function call. Default values are specified when the function is declared.
Eg : float amount(float principle,int period, float rate=0. 15)
Function call is
Value=amount(5000,7);
Here it takes principle=5000& period=7
And default value for rate=0.15
Value=amount(5000,7,0.34)
Passes an explicit value 0f 0.34 to rate
We must add default value from right to left

19.  What are constant arguments?
    
    

Keyword is const. The qualifier const tells the compiler that the function should not modify the argument. The compiler will generate an error when this condition is violated. This type of declaration is significant only when we pass arguments by reference or pointers
eg: int strlen (const char *p);

20.  How the class is specified?
    
    

Generally class specification has two parts
1. Class declaration
    It describes the type and scope of its member
2. Class function definition
    It describes how the class functions are implemented
The general form is
Class class_name
{
private:
variable declarations;
function declaration;
public:
variable declaration;
function declaration;
};

21.  How to create an object?
    
    

Once the class has been declared, we can create variables of that type by using the class name
Eg: classname x; //memory for x is created

22.  How to access a class member?
    We can access the member function by using the following syntax,

object-name. function-name (actual arguments);
eg:x.getdata(100,75.5);

23.  How the member functions are defined?
    
    

Member functions can be defined in two ways

1. Outside the class definition
Member function can be defined by using scope resolution operator ::
General format is

Return type class_ name:: function-name (argument declaration)
{
}

2. Inside the class definition
This method of defining member function is to replace the function declaration by the actual function definition inside the class. It is treated as inline function

Eg: class item
{
int a, b;
void getdata (int x, int y)
{
a=x;
b=y;
};

24.  What is static data member?
    Static variable are normally used to maintain values common to the entire class.
    Feature:
    1. It is initialized to zero when the first object is created. No other   

         initialization is permitted
     2. only one copy of that member is created for the entire class and is   

          shared by all the objects
     3. It is only visible within the class, but its life time is the entire class type   

         and scope of each static member variable must be defined outside the   

         class
     4. It is stored separately rather than objects
          Eg: static int count//count is initialized to zero when an object is created.
          int classname::count; //definition of static data member
 

25.  What is static member function?
    A member function that is declared as static has the following properties
    1. A static function can have access to only other static member declared    

    in the same class
2. A static member function can be called using the classname as follows
    class name :: function_name;

26.  How the objects are used as function argument?
    
    

This can be done in two ways
1. A copy of the entire object is passed to the argument
2. Only address of the objects is transferred to the f unction

27.  What is Friend function? Write the syntax.

A function that has access to the private member of the class but is not itself a member of the class is called friend functions.
The general form is
friend datatype function name (object dec);
Friend function is preceded by the keyword ‘friend’.

28.  Write some properties of friend functions.

                                                                 
1. Friend function is not in the scope of the class to which it has been  

    declared as friend. Hence it cannot be called using the object of that   

    class.
2. Usually it has object as arguments.
3. It can be declared either in the public or private part of a class.
4. It cannot access member names directly. It has to use an object name    

    and dot membership operator with each member name. eg: ( A . x )

     29.  What is function overloading? Give an example.

Function overloading means we can use the same function name to create functions that perform a variety of different tasks.
Eg: An overloaded add( ) function handles different data types as shown below.
// Declarations
i. int add( int a, int b); //add function with 2 arguments of same type
ii. int add( int a, int b, int c); //add function with 3 arguments of same type
iii. double add( int p, double q); //add function with 2 arguments of
different type
//Function calls
add (3 , 4); //uses prototype ( i. )

add (3, 4, 5); //uses prototype ( ii. )
add (3 , 10.0); //uses prototype ( iii. )

29. What is constant function?

When we define the function as constant we should not modify the objects. If the functions are modified to change the values, the error can be caught.

           Syntax:

           < Return type> <Function name> ( ArgList ) const

           {

               Funtion body;

           }

30. What is constant object?

Const objects are objects that are not modifiable. Only functions that are defined as Const can be accessed by const objects. Even public variables of the object are not modifiable.

Syntax:

const class_name obj_name;

31. Define the nested class.

We have two classes. Outside class is a nesting class and contains the entire body of the inside class. The inside class, which is defined inside the outside class is called nested class.

     32. What is the syntax, if we defined the nested class as public?

Class outerClass

{

    public:

     Class innerClass

      {

            ---------

            ---------

      };

            --------

            --------

    };

     32. What is the syntax, if we defined the nested class as private?

Class outerClass

{

    Private:

     Class innerClass;

     Public:

            ---------

            ---------

};

Class outerClass :: innerClass

{

            Definition of innerClass;

            -----------------

            -----------------

}

     33. What is polymorphism? What are its types?

Polymorphism is the ability to take more than one form. An operation may exhibit different behaviors in different. The behavior depends upon the type of data used.
Polymorphism is of two types. They are
1. Function overloading
2. Operator overloading

UNIT – II

1. Define constructor.

A constructor is a special member function whose task is to initialize the objects of its class. It is special because its name is same as class name. The constructor is invoked whenever an object of its associated class is created. It is called constructor because it constructs the values of data members of the class
Eg:
integer Class
{
……
public:
integer( );//constructo r
………
}

2.  Define default constructor.

The constructor with no arguments is called default constructor.
Eg:
Class integer
{
int m,n;
Public:
Integer( );
…….
};
integer::integer( )//default constructor
{
m=0;n=0;
}
the statement
integer a;
invokes the default constructor

3. Define parameterized constructor.

constructor with arguments is called parameterized constructor.
Eg;
class integer
{

int m,n;
    public:
           integer(int x,int y)
           {

m=x;n=y;
}

To invoke parameterized constructor we must pass the initial values as arguments to the constructor function when an object is declared. This is done in two ways,

1.By calling the constructor explicitly
eg: integer int1=integer(10,10);
2.By calling the constructor implicitly
eg: Integer int1(10,10);

4. Define default argument constructor.

The constructor with default arguments are called default argument constructor.
Eg:
Complex(float real,float imag=0);
The default value of the argument imag is 0
The statement complex a(6.0)
assign real=6.0 and imag=0
the statement
complex a(2.3,9.0)
assign real=2.3 and imag=9.0

5.  What is the ambiguity between default constructor and default argument constructor?

The default argument constructor can be called with either one argument or no arguments. When called with no arguments, it becomes a default constructor. When both these forms are used in a class, it cause ambiguity for a statement such as A a;
The ambiguity is whether to call A::A() or A::A(int i=0)

6.  Define copy constructor.

A copy constructor is used to declare and initialize an object from another object. It takes a reference to an object of the same class as an argument
Eg: integer i2(i1);
would define the object i2 at the same time initialize it to the values of i1.
Another form of this statement is
Eg: integer i2=i1;
The process of initializing through a copy constructor is known as copy initialization .

7. Define destructor.

It is used to destroy the objects that have been created by constructor. Destructor name is same as class name preceded by tilde symbol(~)        
Eg;
~integer()
{
}
A destructor never takes any arguments nor it does it return any value. The compiler upon exit from the program will invoke it. new Whenever operator is used to allocate memory in the constructor, we should
use delete to free that memory.

8. Define multiple constructors (constructor overloading).

The class that has different types of constructor is called multiple constructors

Eg:

#include<iostream. h>
#include<conio.h>

class integer
{

int m,n;
public:
integer( ) //default constructor
{

m=0;n=0;
}
integer(int a,int b) //parameterized constructor
{

m=a; n=b;
}
integer(&i) //copy constructor
{

m=i. m;

n=i.n;
}

};
void main()
{

integer i1; //invokes default constructor
integer i2(45,67);//invokes parameterized constructor
integer i3(i2); //invokes copy constructor

}

9.  Write some special characteristics of constructor.

Special characteristics of constructor are,
1. They should be declared in the public section
2. They are invoked automatically when the objects are created
3. They do not have return types, not even void and therefore, and they

     cannot return values
4.They cannot be inherited, though a derived class can call the base class
5. They can have default arguments
6. Constructors cannot be virtual f unction

10.  How the objects are initialized dynamically?

To call parameterized constructor we should the pass values to the object ie,for the constructor integer(int a,int b) it is invoked by integer a(10,18)
this value can be get during run time. i.e., f or above constructor
int p,q;
cin>>p>>q;
integer a(p,q);

11.  What is operator overloading?

This mechanism of giving such special meanings to an operator is known as Operator overloading. It provides a flexible option for the creation of new definitions for C++ operators.

12.  List out the operators that cannot be overloaded.
    1.  Class member access operator (., .*)
    2.  Scope resolution operator (::)
    3.  Size operator (sizeof)
    4.  Conditional operator (? :)

13.  List out the operators that cannot be overload as friend functions.

a.    Assignment operator =

b.    Function call operator ()

c.    Array subscript operator []

d.    Access to class member using pointer to object operator ->

14.  What is the purpose of using operator function? Write its syntax.

To define an additional task to an operator, we must specify what it means in relation to the class to which the operator is applied. This is done by Operator function , which describes the task. Operator functions are either member functions or friend functions. The general form is
return type classname :: operator op(arglist )
{
      function body
}
where return type is the type of value returned by specified operation.
Op- operator being overloaded. The op is preceded by a keyword operator. operator op is the function name.

15.  Write at least four rules for Operator overloading.

Rules for Operator overloading are,
1.  Only the existing operators can be overloaded.
2.  The overloaded operator must have at least one operand that is of user    

     defined data type.
3.  The basic meaning of the operator should not be changed.
4.  Overloaded operators follow the syntax rules of the original operators.   

5. They cannot be overridden.

16. What are the different types of conversion?

     The different types of conversions are,

1.    Basic type to Class type.

2.    Class type to Basic type.

3.    Class type to Class type.

4.    Basic type to Basic type

17. Write the syntax to convert from class to basic type.

Operator typename( )

{

            …………

            Function statements;

            …………

}

       

18. What are the conditions to satisfy the type casting function?

1.    it must be a class member.

2.    it must not specify a return type.

3.    it must not have any arguments.