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1 INTERNAL ASSESSMENT TEST 1(Solutions) Date :01/03/2017 Max Marks: 40 Subject& Code: Object Oriented Concepts (15CS45) Sem:VII ISE Name of the faculty: Miss Pragyaa Time: 90 minutes Note: Answer to all sevenquestions Question Questions Marks No. 1. a. What is procedure oriented and object oriented programming language? List out the disadvantages of procedure oriented programming languages. 5 Answer Procedure oriented programming language:- Procedural oriented programming is a list or set of instructions telling a computer what to do step by step and how to perform from the one code to the next code. It focuses on the process rather than data. Procedural programming languages include C, C++, Go, Fortran, Pascal and BASIC. Features : Emphasis on non-real item Programs are divided into functions Data are sharable Structured Programming Top-Down Approach Object Oriented Programming:- Object Oriented Programming is a method of visualizing and programming the problem in a global way. Object oriented programming is a technique to envision the problem as a collection of objects that represents real world entities Features : Emphasis is on data rather than procedure Programs are divided into objects Functions that operate on the data of the object are tied together in data structure Data is hidden and cannot be accessed by external functions Objects may communicate with each other using functions Drawback of procedure oriented programming:- Data is not secure. It can be manipulated by any procedures Debugging is tough and hectic. Associated functions that were designed by library programmerr don t have rights to work upon the data. They are not a part of structure definition itselfbecause application

2 program might modify the structure variables by some inadvertently written in application program itself. code b. Differentiate between C and C++. Answer C++ is the extension of C. It is the proper superset of C language. C++ compiler can compile programs written in C language but reverse is not true. Decision making constructs, looping constructs, structures, functions are used in the same way in C++ as in C language. Apart from these there are additional keywords provided by C++. C C C compiler cannot programs execute C++ 2. In C, u may / may not include function prototypes 3. C doesn t allow for default arguments 4. Declaration of the variables must be at the beginning 5. If a C program usess a Local variable that has Same name as global variable, then C uses the value of a local variable. 1. C++ compiler can execute C programs 2. In C++, you must Include function prototypes 3. C++ lets you to specify default arguments in function prototype 4. Declaration of the variables can be anywhere before using 5. In C++, u can instruct program to use value of global variable with scope resolution Eg- cout<< Iamglobalvar : << ::I; 6. Function inside the structure is not allowed 7. Object initializationn doesn t exist 8. Data hiding, data abstraction and data encapsulation feature doesn t exist 6. Function inside the structure is allowed 7. Object initialization (constructor) exist 8. Data hiding, data abstraction and data encapsulation exists in C++ 2. Write a program to swap two integers using a) reference variable 8

3 Answer b) call by reference (using pointers). a) using reference variable #include<iostream.h> #include<conio.h> void swap (int &a, int &b) /* &a and&b are reference variables */ int temp; temp=a; a=b; b=temp; main() clrscr(); int i=5,j=10; cout<<"before swapping I = "<<i<<" J = "<<j<<endl; swap(i,j); cout<<"after swapping I = "<<i<<" J = "<<j<<endl; b) call by reference #include<iostream.h> #include<conio.h> void swap(int *, int *); void main() int x=5, y=7; swap(&x, &y); cout<<x<<y<<<*a<<* *b; void swap(int *a, int *b) int t=*a; *a=*b; *b=t; cout<<*a<<*b; 3. The marks obtained by a student in 5 different subjects are taken as input through the keyboard. The student gets a division as per the following rules: 8

4 Percentage above or equal to 60 - First division Percentage between 50 and 59 - Second division Percentage between 40 and 49 - Third division Percentage less than 40 Fail. Write a program to calculate the division obtained by the student in C++ Answers #include<stdio.h> void main( ) int m1, m2, m3, m4, m5, per ; cout<< "Enter marks in five subjects " ; cin>>m1>>m2>>m3>> >m4>>m5 ; per = ( m1 + m2 + m3 + m4 + m5 ) / 5 ; if ( per >= 60 ) cout<< "First division" ; else if ( ( per >= 50 ) && ( per < 60 ) ) cout<< "Second division" ; else if ( ( per >= 40 ) && ( per < 50 ) ) cout<<"third division" ; else cout<< "Fail" ; 4. What do you mean by function overloading? Write a program to calculate area of square and rectangle, demonstrating the concept of function overloading. Answer Overloading refers to the use of same thing for different purposes.we can use the same function name to create functions that performs variety of different tasks, called function overloading (polymorphism).they must have different signatures. Signature of a function means the number, type and sequence of formal arguments of a function.function overloading is also called as function polymorphism. It is static in nature because the function definition to be executed is selected by the compiler during compile time itself. #include<iostream.h> 8

5 Class Test int side, length, breath; int area(int); int area(int, int); ; int Test::area(int side) return side*side; int Test::area(int length, int breath) return length*breath; void main() Test t; t.area(5); t.area(4, 5); 5. Differentiate between the following with example a) Inline functionn and macros b) Constant function and member function. Answer a) Inline functionn and macros The major difference between inline functions and macros is the way they are handled. Inline functions are parsed by the compiler, whereas macros are expanded by the C++ preprocessor.a macro is a fragment of code which has been given a name. Macros are poor predecessor to inline functions. An inline function is a function that is expanded in line when it is invoked(or called). i.e. the compiler replaces (similar to the macros expansion).the fact that macros use text replacement creates the potential for bugs.for example, a macro for cubing a number is defined as: # define cube(x) x*x*x the function call with the corresponding functionn code Here a mere text substitution takes place with x being replaced by the macro 8

6 parameter. For example: 1. A= cube(5.0); //replaced by A=5.0*5.0*5.0; 2. C= cube (x++); // replaced by C= x++*x++*x++ cube(x++) undesirably increments x thrice. But the inline cube() function evaluates x, passes the value to be cubed, and correctly increments x once. b) Constant function and member function. The Library Programmer may desire that one of member functions of his/her class shouldn t be able to change the value of member Data. Function should merely read values contained in the datamembers, but not change them even accidentally while defining the function.compiler s help may be sought by declaring function as constant Function & attempting to change data value through member Function, the compiler may throw an error.member functions are specified as constants by suffixing prototype and function definition header with const keyword.for const. member functions, memory occupied by invoking object is a read-only memory. #include<iostream> using namespace std; class Test int value; public: Test(int v = 0) value = v; int getvalue() const value =value+10; //compile time error, can t modify the private variable return value; ;

7 Member functions of a class are the function that belongs to a particular class. A member function by default has right to access the private data member of the class to which it is a member of. #include<iostream> using namespace std; class Test int value; public: Test(int v = 0) value = v; int getvalue() value = value+10; //no compile time error return value; ; int main() Test t(20); cout<<t.getvalue(); return 0; 6. a What is a constructor? Explain different types of constructor with example. 5 Answer A constructor is a special member function whose task is to initialize the object of a class. Its name is same as the class name. A constructor does not have a return type. A constructor is called or invoked when the object of its associated class is created. It is called constructor because it constructs the values of data members of the class.

8 A constructor cannot be virtual A constructor can be overloaded. There three types of constructor: (i) Default Constructor The constructor which has no arguments is known as default constructor. (ii) Parameterized Constructor The constructor which takes some argument is known as parameterized constructor.if programmer wants to pass some initial values for the data members contained in the object, then he uses a parameterized constructor (iii) Copy constructor The constructor whichh takes reference to its own class as argument is known as copy constructor.it is special type of parameterized constructor.as the name implies, it copies one object to another.it is called when an object is created and equated to an existing object at the same time. Example:- #include<iostream.h> class Add int x, y, z; public: Add() //default constructor Add(int a, int b) //parameterized constructor x=a; y=b; Add(Add &); void calculate(void); void display(void); ; Add :: Add(Add &p) //copy constructor x=p.x; y=p.y; cout<< Value of x and y for new object: <<x<< and <<y<<endl; void Add :: calculate()

9 z=x+y; void Add :: display() cout<<z; void main() Add a(5, 6); Add b(a); b.calculate(); b.display(); b Explain destructors. Answer It is a special member function which is executed automatically when an object is destroyed. Its name is same as class name but it should be preceded by the symbol ~. It cannot be overloaded as it takes no argument. It is used to delete the memory space occupied by an object. It has no return type. It should be declared in the public section of the class. Example:- #include <iostream.h> Using namespace std; class XYZ int x; public: XYZ( ); ~XYZ( ); void display( ); ; XYZ::XYZ( ) x=9; XYZ:: ~XYZ( ) 3

10 cout<< object is destroyed ; void display() Cout<<x; void main() XYZ xyz; xyz.display(); 7. Explain friend member function, friend nonmember function and friend class with example. 8 Answer Friend nonmember function:- A Friend function is a non-member function that has special rights to access private data members of any object of class of whom it is a friend.friend function is prototyped within the definition of class of which it is intendedd to be friend.it is prefixed with the keyword friend.since it is a non-member function, it is defined without using scope resolution operator. It is not called with respect to an object. Class A Int x; Public: friend void abc(a); ; Void abc(a a1) a1.x++; Void main A a1; abc(a1); Friend member function:- We can make a member function of a particular class a friend of another class. This helps only that friend function access the private data member of another

11 class of which it is a friend of. Class A Int x; Public: friend void B:: :abc( ); ; Class B void abc(); ; void B::abc( ) x++; void main B b1; b1.abc( ); Friend class:- A class can be friend of another class.member Functions of a friend class can access private data members of objects of class of which it is a friend. Example:- Class B; Class A int x; Public: void add(int,int); friend class B; //declaring class B as a friend of A ; Class B Public: void display(int); void mul(int,int ); ; void B :: display(int);

12 Cout<<x; Void B :: multiply(int a,int b) x=a*b; Cout<<x; //accessing private data member

C++ 8. Constructors and Destructors

C++ 8. Constructors and Destructors 8. Constructors and Destructors C++ 1. When an instance of a class comes into scope, the function that executed is. a) Destructors b) Constructors c) Inline d) Friend 2. When a class object goes out of