INTRODUCTION TO C++
PROGRAMMING LAB
MANUAL (P22PLC2054)
Prepared by,
Smt. S.K. Uma,
Associate Professor
DEPARTMENT OF COMPUTER SCIENCE
AND ENGINEERING
LAB OBJECTIVE
• Introduces object-oriented programming concepts using the C++ language.
• Introduces the principles of data abstraction, inheritance and polymorphism;
• Introduces handling of files and exception handling
Lab Exercises
Q.No. Problem Statement CO, PO,PSO
1. Write a C++ program to sort the elements in Co1,Po1,Po2,P03,Po5,PSo1
ascending and descending order.
2. Write a C++ program to find the sum of all the Co1,Po1,Po2,P03,Po5,PSo1
natural numbers from 1 to n.
3. Write a C++ program to swap 2 values by writing a Co1,Po1,Po2,P03,Po5,PSo1
function that uses call by reference technique.
4. Write a C++ program to demonstrate function Co1,Po1,Po2,P03,Po5,PSo1
overloading for the following prototypes. add(int a,
int b) add(double a, double b)
5. . Create a class named Shape with a function that Co3,Po1,Po2,P03,Po5,PSo1
prints "This is a shape". Create another class named
Polygon inheriting the Shape class with the same
function that prints "Polygon is a shape". Create two
other classes named Rectangle and Triangle having
the same function which prints "Rectangle is a
polygon" and "Triangle is a polygon" respectively.
Again, make another class named Square having the
same function which prints "Square is a
rectangle".Now, try calling the function by the object
of each of these classes.
6. Suppose we have three classes Vehicle, FourWheeler, Co3,Po1,Po2,P03,Po5,PSo1
and Car. The class Vehicle is the base class, the class
FourWheeler is derived from it and the class Car is
derived from the class FourWheeler. Class Vehicle
has a method 'vehicle' that prints 'I am a vehicle',
class FourWheeler has a method 'fourWheeler' that
prints 'I have four wheels', and class Car has a
method 'car' that prints 'I am a car'. So, as this is a
multi-level inheritance; we can have access to all the
other classes methods from the object of the class
Car. We invoke all the methods from a Car object and
print the corresponding outputs of the methods. So, if
we invoke the methods in this order, car(),
fourWheeler(), and vehicle(), then the output will be
16-2-2023 3 I am a car I have four wheels I am a
vehicle Write a C++ program to demonstrate
multilevel inheritance using this.
7. Write a C++ program to create a text file, check file Co4,Po1,Po2,P03,Po5,PSo1
created or not, if created it will write some text into
the file and then read the text from the file.
8. Write a C++ program to write and read time in/from Co4,Po1,Po2,P03,Po5,PSo1
binary file using fstream
9. Write a function which throws a division by zero Co4,Po1,Po2,P03,Po5,PSo1
exception and catch it in catch block. Write a C++
program to demonstrate usage of try, catch and throw
to handle exception.
10. Write a C++ program function which handles array of Co4,Po1,Po2,P03,Po5,PSo1
bounds exception using C++.
Introduction
Concepts of Object Oriented programming using C++
1.Classes and Objects:
A class is a user defined data type. Object is an instance of that class. By default the members are
private.
Syntax of class declaration
class classnamename
public:
data members;
method members;
private:
data members;
method members;
};
Ex:
class Student
string name;
public:
void read()
cin>>name;
void display()
cout<<name;
};
Syntax for object declaration
Classname variable;
Ex: Student s;
Private members are not accessible outside the class. But public members are accessible
outside the class. To access the members of a class first the object of that class is created.
Then the object name and dot( . ) operator is used.
Ex. sdisplay();
2.Abstraction and Encapsulation
• Hiding implementation details is called abstraction. Encapsulation is Binding data
and method as single unit . In the above example data(name)and methods(read( )and
display()) are put together.
3.Inheritance
one class inherits all the attributes of some other class.
Types of inheritance:
1.Single level 2. Multilevel 3.Multiple 4. Hierarchical 5. Hybrid inheritance.
4.Polymorphism:
It is the ability of a single object to appear in many forms.
Types of Polymorphism
1.Compile time Polymorphism (Function overloading and Operator overloading)
The resolution of the function happens at compile-time
2.Run time Polymorphism (Function Overriding)
The resolution of the function happens at compile-time
3.Parametric Polymorphism(Templates)
Exception
Exceptions are runtime anomalies or abnormal conditions that a program encounters .
Exception handling in C++ consist of three keywords: try , throw and catch .All
exceptions are derived from std::exception class.
try - code that may raise an exception
throw - throws an exception when an error is detected
catch - code that handles the exception thrown by the throw keyword
The basic syntax for exception handling in C++ is given below:
try{
//code that may raise an exception
throw argument;
}
catch(exception){
//code to handle exception
}
Here, we have placed the code that might generate an exception inside the try block. Every
try block is followed by the catch block.
When an exception occurs, the throw statement throws an exception, which is caught by
the catch block.
The catch block cannot be used without the try block.
Advantage
It maintains the normal flow of the application. In such case, rest of the code is executed even
after exception.
File Handling
File handling is a mechanism to store the output of a program in a file and help perform
various operations on it. Files help to store these data permanently on a storage device. The
term “Data” is commonly referred to as known facts or information. In the present era, data
plays a vital role.
Types of file
1.binary file 2.text file
File processing consists of creating, storing, and/or retrieving the contents of a file .
File handling functions:
fprintf(), fscanf(), fgetc(), fputc(), fgets(), fputs() will help you in writing and reading to a
file.
The fstream library allows us to work with files. Functions for file handling.
There are three classes included in the fstream library, which are used to create, write or read
files:
class Description
oftream Creates and writes to files
ifstream Reads from files
fstream Acombination of ofstream and ifstream:creates,reads and writes to files
File Opearations:
No. Function Description
1 open() This is used to create a file.
2 read() This is used to read the data from the file
3 write() reads data from the file
4 close() This is used to close the file.
Syntax for opening a file
open( FileName , Mode );
Syntax for writing into a file
FileName<<"Insert the text here";
Syntax for reading from a file
FileName>>Variable
Syntax for closing a file
FileName.close();
Compiling C++ source code into machine-readable code consists of the following four
processes:
1. Preprocessing the source code.
2. Compiling the source code.
3. Assembling the compiled file.
4. Linking the object code file to create an executable file.
The following diagram shows C++ compilation process.
IDE Used:code blocks
Code Blocks:
It is a cross platform that supports compiling and running multiple programming languages.
It can work with a variety of compilers.
Steps for using code blocks
1.click code blocks icon on the desktop
2.select <file>select <new> and then select <project>
3.Double click <console application>
4. click <next> and select <c++>
5.Write the project name in <project title>, write the path or folder to create project.
6. click <next>
7. click <finish>
8. workspace is created with the given project name
9.Double click Sources main.cpp file is created. Double click main.cpp template for main is
created. Then start writing program
10.After entering the program save it.
11.click on <build> to compile the program
12.click on <run> button to execute the program.
Program 1. Write a C++ program to find the sum of all the natural numbers from 1 to n.
#include <iostream>
using namespace std;
void naturalsum(int n)
int sum=0, i;
for(i=1;i<=n;i++)
sum=sum+i;
cout<<"sum of first "<< n <<" natural numbers : "<<sum<<endl;
int main()
int n;
cout<<"enter the value of n: ";
cout<<endl;
cin>>n;
naturalsum(n);
Sample Intput:
enter the value of n:
Output:
sum of first 5 natural numbers : 15
Program 2. Write a C++ program to sort the elements in ascending and descending order.
#include <iostream>
using namespace std;
//method to sort elements in ascending order
void ascending(int a[],int n)
int i,j,temp;
for(i=0;i<n-1;i++)
for(j=0;j<n-1-i;j++)
if(a[j]>a[j+1])
temp=a[j];
a[j]=a[j+1];
a[j+1]=temp;
//method to sort elements in descending order
void descending(int a[],int n)
int i,j,temp;
for(i=0;i<n-1;i++)
for(j=0;j<n-1-i;j++)
{
if(a[j]<a[j+1])
temp=a[j];
a[j]=a[j+1];
a[j+1]=temp;
//main method
int main()
int a[10],n, i,choice;
char ch;
do
cout<<"enter the size of the array";
cin>>n;
cout<<"enter the elements";
for(i=0;i<n;i++)
cin>>a[i];
cout<<"elements before sorting";
cout<<endl;
for(i=0;i<n;i++)
cout<<a[i]<<" ";
cout<<endl;
cout<<"1. ascending order sort 2. descending order sort";
cout<<endl<<"enter your choice: ";
cin>>choice;
switch (choice)
case 1:
cout<<"elements after sorting";
ascending(a,n);
cout<<endl;
cout<<endl;
for(i=0;i<n;i++)
cout<<a[i]<<" ";
break;
case 2:
cout<<"elements after sorting";
descending(a,n);
cout<<endl;
cout<<endl;
for(i=0;i<n;i++)
cout<<a[i]<<" ";
break;
default: cout<<"invalid option";
cout<<endl<<"do u want to continue y/n";
cin>>ch;
}while(ch=='y'|| ch=='Y');
cout<<"bye";
Sample Input
enter the size of the array
enter the elements
23
67
88
11
elements before sorting
23 67 8 11
1. ascending order sort 2. descending order sort
enter your choice: 1
elements after sorting
Output:
8 11 23 67
do u want to continue y/n y
Program 3: Write a C++ program to swap 2 values by writing a function that uses call by reference
technique
#include <iostream>
using namespace std;
void swap(int &p,int &q)
int temp;
temp=p;
p=q;
q=temp;
int main()
int a,b;
cout<<"enter the two numbers"<<endl;
cin>>a>>b;
cout<<"Elements before swapping"<<endl;
cout<<"a= "<<a<<endl;
cout<<"b= "<<b<<endl;
swap(a,b);
cout<<"Elements after swapping"<<endl;
cout<<"a= "<<a<<endl;
cout<<"b= "<<b<<endl;
return 0;
}
Sample input:
Enter two numbers
10 20
Elements before swapping
a=10
b=20
Output:
Elements after swapping
a=20
b=10
OR
Call by address program
#include <iostream>
using namespace std;
void swap(int *p,int *q)
int temp;
temp=*p;
*p=*q;
*q=temp;
int main()
int a,b;
cout<<"enter the two numbers"<<endl;
cin>>a>>b;
cout<<"elements before swapping"<<endl;
cout<<"a= "<<a<<endl;
cout<<"b= "<<b<<endl;
swap(&a,&b);
cout<<"elements after swapping"<<endl;
cout<<"a= "<<a<<endl;
cout<<"b= "<<b<<endl;
return 0;
Sample input:
Enter two numbers
10 20
Elements before swapping
a=10
b=20
Output:
Elements after swapping
a=20
b=10
Program 4: . Write a C++ program to demonstrate function overloading for the following
prototypes. add(int a, int b) add(double a, double b)
#include <iostream>
using namespace std;
void add(int p,int q)
int c;
c=p+q;
cout<< c;
void add(double p,double q)
double c;
c=p+q;
cout<< c;
int main()
int a,b;
double x,y;
cout<<"enter two integer numbers";
cin>>a>>b;
cout<<a<<"+"<<b<<"=";
add(a,b);
cout<<endl<<"enter two double numbers";
cin>>x>>y;
cout<<x<<"+"<<y<<"=";
add(x,y);
return 0;
Sample Input:
enter two integer numbers: 12 34
Output
12+34=46
Sample Input:
enter two double numbers: 6.7 8.9
Output:
6.7+8.9=15.6
Program 5. Create a class named Shape with a function that prints "This is a shape". Create
another class named Polygon inheriting the Shape class with the same function that prints "Polygon
is a shape". Create two other classes named Rectangle and Triangle having the same function which
prints "Rectangle is a polygon" and "Triangle is a polygon" respectively. Again, make another class
named Square having the same function which prints "Square is a rectangle".Now, try calling the
function by the object of each of these classes.
#include <iostream>
using namespace std;
class Shape
public:
void display()
cout<<endl<< "This is a shape";
};
class Polygon:public Shape
public:
void display()
Shape::display();
cout<<endl<< "Polygon is a shape";
};
class Rectangle:public Polygon
public:
void display()
Shape::display();
cout<< endl<<"Rectangle is a Polygon ";
};
class Triangle:public Polygon
public:
void display()
Shape::display();
cout<< endl<<"Triangle is a Polygon ";
};
class Square:public Rectangle
public:
void display()
Shape::display();
cout<< endl<<"Square is Rectangle ";
};
int main()
Polygon p;
Rectangle r;
Triangle t;
Square sq;
p.display();
r.display();
t.display();
sq.display();
return 0;
Output:
This is a shape
Polygon is a shape
This is a shape
Rectangle is a Polygon
This is a shape
Triangle is a Polygon
This is a shape
Square is Rectangle
Program 6 Suppose we have three classes Vehicle, FourWheeler, and Car. The class Vehicle is the
base class, the class FourWheeler is derived from it and the class Car is derived from the class
FourWheeler. Class Vehicle has a method 'vehicle' that prints 'I am a vehicle', class FourWheeler has
a method 'fourWheeler' that prints 'I have four wheels', and class Car has a method 'car' that prints 'I
am a car'. So, as this is a multi-level inheritance; we can have access to all the other classes methods
from the object of the class Car. We invoke all the methods from a Car object and print the
corresponding outputs of the methods. So, if we invoke the methods in this order, car(),
fourWheeler(), and vehicle(), then the output will be I am a car I have four wheels I am a vehicle
Write a C++ program to demonstrate multilevel inheritance using this.
#include <iostream>
using namespace std;
class Vehicle
public:
void vehicle()
cout<<"i am a vehicle"<<endl;
};
class FourWheeler:public Vehicle
public:
void fourwheeler()
cout<<"i have four wheels"<<endl;
};
class Car:public FourWheeler
{
public:
void car()
cout<<"i am a car"<<endl;
};
int main()
Car c;
c.vehicle();
c.fourwheeler();
c.car();
return 0;
Output:
i am a vehicle
i have four wheels
i am a car
Program 7: Write a C++ program to create a text file, check file created or not, if created it will
write some text into the file and then read the text from the file.
#include <iostream>
using namespace std;
int main()
fstream file; //object of fstream class
//opening file "sample.txt" in out(write) mode
file.open("sample.txt",ios::out);
if(!file)
cout<<"Error in creating file!!!"<<endl;
return 0;
cout<<"File created successfully."<<endl;
//write text into file
file<<"ABCD.";
//closing the file
file.close();
//again open file in read mode
file.open("sample.txt",ios::in);
if(!file)
{
cout<<"Error in opening file!!!"<<endl;
return 0;
//read untill end of file is not found.
char ch; //to read single character
cout<<"File content: ";
while(!file.eof())
file>>ch; //read single character from file
cout<<ch;
file.close(); //close file
return 0;
Output: ABCD..
Program 8: Write aC++ program to write and read time in/from binary file using fstream
#include <iostream>
#include <fstream>
#include <iomanip> //for setfill() and setw()
using namespace std;
#define FILE_NAME "time.dat"
//function to write time into the file
void writeTime(int h, int m, int s){
char str[10];
fstream file;
file.open(FILE_NAME, ios::out|ios::binary);
if(!file){
cout<<"Error in creating file!!!"<<endl;
return;
}
//make string to write
sprintf(str,"%02d:%02d:%02d",h,m,s);
//write into file
file.write(str,sizeof(str));
cout<<"Time "<<str<<" has been written into file."<<endl;
//close the file
file.close();
//function to read time from the file
void readTime(int *h,int *m, int *s){
char str[10];
int inH,inM,inS;
fstream finC;
finC.open(FILE_NAME,ios::in|ios::binary);
if(!finC){
cout<<"Error in file opening..."<<endl;
return;
}
if(finC.read((char*)str,sizeof(str))){
//extract time values from the file
sscanf(str,"%02d:%02d:%02d",&inH,&inM,&inS);
//assign time into variables, which are passing in function
*h=inH;
*m=inM;
*s=inS;
}
finC.close();
}
int main(){
int m,h,s;
cout<<"Enter time:\n";
cout<<"Enter hour: "; cin>>h;
cout<<"Enter minute: "; cin>>m;
cout<<"Enter second: "; cin>>s;
//write time into file
writeTime(h,m,s);
//now, reset the variables
h=m=s=0;
//read time from the file
readTime(&h,&m,&s);
//print the time
cout<<"The time is
"<<setw(2)<<setfill('0')<<h<<":"<<setw(2)<<setfill('0')<<m<<":"<<setw(2)<<setfill('0')<<s
<<endl;
return 0;
}
Input:
Enter time:
Enter hour:12
Enter minute:32
Enter second:22
Output:
Time 12:32:22 has been written into file
The time is 12:32:22
Program9. Write a function which throws a division by zero exception and catch it in catch block.
Write a C++ program to demonstrate usage of try, catch and throw to handle exception.
#include <iostream>
using namespace std;
void divide(int a,int b)
if(b!=0)
int c=a/b;
cout<<endl<<"result="<<c;
else
throw(b);
int main()
try
divide(4,3);
divide(4,0);
catch(int e)
cout<<endl<<"divide by zero";
return 0;
}
Sample Input:
43
Output :
result=1
input:
40
Output:
divide by zero
Program 10: Write a C++ program function which handles array of bounds exception using C++.
#include <iostream>
using namespace std;
void check_array_index(int a[10],int n,int i)
try
if (i>=0 && i<n)
cout<<"the element at position "<<i<<" is: "<<a[i];
else
throw i;
catch(int e)
cout<<endl<<"array index out of bound";
int main()
int a[10],n,pos;
cout<<"enter the size of an array : ";
cin>>n;
cout<<"enter the elements of an array "<<endl;
for(int i=0;i<n;i++)
cin>>a[i];
cout<<"enter the index of element in an array : ";
cin>>pos;
check_array_index( a, n, pos);
return 0;
Output:
Run 1:
Sample input:
enter the size of an array : 3
enter the elements of an array
89
56
77
enter the index of element in an array: 2
Output:
the element at position 2 is: 7
Run 2:
Sample input:
enter the size of an array : 4
enter the elements of an array
33
44
67
98
enter the index of element in an array: 5
Output:
array index out of bound
