File Handling: Reading and Writing into a text file using class

Code

#include<iostream>
#include<fstream>
#include<string>
#include<conio.h>
using namespace std;

class marks
{
      private:
              int oop;
              int cal;
              int dis;
              int s;
              int a;
             
      public:
             marks():oop(0),cal(0),dis(0)
               {    }
           
             void getdata()
             {
                  cout<<"Enter marks of oop: ";
                  cin>>oop;
                  cout<<"Enter marks of cal: ";
                  cin>>cal;
                  cout<<"Enter marks of dis: ";
                  cin>>dis;
             }
           
             void display()
             {
                  cout<<"OOP = "<<oop<<endl;
                  cout<<"Cal = "<<cal<<endl;
                  cout<<"Dis = "<<dis<<endl;
             }
};

int main ()
{
    marks m;
    int s;
   
    m.getdata();
                                                        //opening the file in binary mode
    ofstream myfile("Writing_Reading_class.txt",ios::binary);        
                                                     
                                                       //writing in the file
    myfile.write(reinterpret_cast<char *>(&m),sizeof(m));
                 //closing the file
    myfile.close();
                                                      //re-opening the file in binary mode
    ifstream my("Writing_Reading.txt",ios::binary);
                                                      //Reading from the file
    my.read(reinterpret_cast<char *>(&m),sizeof(m));
             //display
    m.display();
   
    cout << "\n\nPress any key to close.";
    getch ();
    return 0;
}

Output

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File Handling: Reading and Writing into a binary text file

Code:

#include<iostream>
#include<fstream>
#include<string>
#include<conio.h>
using namespace std;

int main()
{
    int max = 10;
    int a[max];
 
    ofstream myfile("Writing_Reading.txt",ios::binary);        //opening the file in binary mode
 
    for(int j=0;j<max;j++)                                     //assigning values(array)
            a[j] = (j + 1);
         
                                                       //writing in the file
    myfile.write(reinterpret_cast<char *>(a),sizeof(a));
    cout<<"File written."<<endl<<endl;
 
    myfile.close();                                   //closing the file
 
    ifstream my("Writing_Reading.txt",ios::binary);        //opening the file in binary mode
 
                                                      //Emptying the array
    for(int j=0;j<max;j++)
            a[j] = 0;
                                                      //Reading from the file
    my.read(reinterpret_cast<char *>(a),sizeof(a));
 
    for(int j=0;j<max;j++)                             //display array
            cout<<a[j];
 
    cout<<endl<<"Press any key to exit.";
    getch();
    return 0;
}

Output:

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find index number of the largest element using class

Problem

Start with a program that allows the user to input a number of integers, and then stores them in an int array. Write a function called maxint() that goes through the array, element by element, looking for the largest one. The function should take as arguments the address of the array and the number of elements in it, and return the index number of the largest element. The program should call this function and then display the largest element and its index number.

Code

// p[4].cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#include<conio.h>
#include<iostream>
#include<string.h>
using namespace std;

class intgrs
{
private:
int a[5];
int i,j,z;

public:
intgrs():j(0),i(0),z(0)
{ }

void maxint()
{
cout<<"Enter Integers: ";
for(i=0; i<5; i++)
{
cin>>a[i];
}
for(i=0;i<5;i++)
{
if(a[i]>j)
{
j = a[i];
z=i;
}
}
cout<<"\n\nLargest Element = "<<j;
cout<<"\n\nIndex Number = "<<(z+1)<<endl;
}
};

int main()
{
intgrs i;

i.maxint();

cout<<"\n\nPress any key to close.";
getch();
return 0;
}

Output

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Input and display employee data of 100 employees using array of objects

Problem

Create a class called employee that contains a name (an object of class string) and an employee number (type long). Include a member function called getdata() to get data from the user for insertion into the object, and another function called putdata() to display the data. Assume the name has no embedded blanks.
Write a main() program to exercise this class. It should create an array of type employee, and then invite the user to input data for up to 100 employees. Finally, it should print out the data for all the employees.

Code

#include "stdafx.h"
#include<conio.h>
#include<iostream>
#include<string.h>
using namespace std;

class employee
{
private:
char name[50];
long no;

public:
employee():no(0)
{ }

void getdata()
{
fflush(stdin);
cout<<"\nEnter Employee Data:\n";
cout<<"Enter Name: ";
cin.get(name,50);
fflush(stdin);
cout<<"Enter Number: ";
cin>>no;
fflush(stdin);
}

void putdata()
{
cout<<"\n\nName= "<<name<<"\nE.number = "<<no<<endl;
}

};

int main()
{
int array_length = 3;
employee e1[array_length];

for(int i=0;i<array_length;i++){
e1[i].getdata();
fflush(stdin);
}

for(int i=0;i<array_length;i++){
e1[i].putdata();
}

cout<<"\n\nPress any key to close.";
getch();
return 0;
}

Output

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Reverse input string in c++

Problem

Take a string input from user and reverse it using C++ language.

Code

// P[1].cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#include<conio.h>
#include<iostream>
#include<string.h>
using namespace std;

class rvrstr
{
private:
char str1[80];
char str2[80];
int i,j,n;
char ch;

public:
rvrstr(): i(0),j(0),n(0)
{ }

void setstr()
{
cout<<"Enter string: ";
cin.get(str1,80);
}

void reversit()
{
n = strlen(str1);
cout<<"\n\nReversed String: ";
for(i=n;i>=0;i--)
{
str2[j] = str1[i];
cout<<str2[j];
j++;
}
}
};

int main()
{
rvrstr r1;

r1.setstr();
r1.reversit();

cout<<"\n\nPress any key to close.";
getch();
return 0;
}

Output

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Electronic Polling System in C++ Language

Problem

Implement (a part of) electronic Pakistani election Scenario where following political parties are participating in election: PPP, PML and PTI.  Create a class PollingStation where it stores the vote’s count, against each party, cast by the Pakistani legal registered voters.  Your program must query the voter for its ID card number before he/she cast the vote and check it against voter list. (Suppose voter list is already with you). If voter is not found in the voter’s list, your program throws the exception IllegalVoter() and discard that voter. The Application again starts working in normal state and terminates only when user wants to quit it. At the end of the day (or whenever user wants) it generates report about the vote count against each party including header that contains date, day and location.

Code

// Poling station.cpp : Defines the entry point for the console application.
//
                      //HEADER FILES
#include "stdafx.h"   //ESSENTIAL TO WORK ON VISUAL STUDIO
#include<fstream>     //FOR FILE
#include<conio.h>     //FOR GETCH FUNCTION
#include<string>      //fOR STRINGS USAGE
#include<iostream>    //FOR COUT AND CIN
using namespace std;
                      //CLASS BEGINS
class PollingStation
{
private:            //VARIABLES DECLARED PRIVATLY, ONLY ACCESSABLE IN THIS CLASS
int votes_count_ppp;
int votes_count_pml;
int votes_count_pti;
int total_votes,hr,mn,sc,flag,choice,offset;
string line,day,location;

public:    //EXCEPTION CLASS
class IllegalVoter
{     };
     //CONSTRUCTOR OF POLLING STATION CLASS
    PollingStation(): votes_count_ppp(0), votes_count_pml(0), votes_count_pti(0),total_votes(0),
                 hr(0),mn(0),sc(0),flag(0),line(""),choice(0)
{ }
          //DESTRUCTOR OF POLLING STATION CLASS
~PollingStation()
{
cout<<"polling Station Destructor";
}
          //GETING THE DATA FROM USER(DAY,DTAE & LOCATION)
void start()
    {                  //GET DAY
         system("cls");
         cout<<"Enter Day: ";
         cin>>day;
                      //GET LOCATION
         system("cls");
         cout<<"\nEnter Location: ";
         cin>>location;
                       //GET TIME
         system("cls");
         cout<<"\nEnter time: "<<endl;
         cout<<"Enter Hour: ";
         cin>>hr;
         cout<<"Enter Minutes: ";
         cin>>mn;
    }
          //CHECKING WHETHER THE PERSON IS ILLEGIBEL FOR VOTE
    void checkdata(string search)
    {
         ifstream Myfile;    //OPENING THE FILE FOR READING
         Myfile.open ("VOTERS_LIST.txt");
         {
         if(Myfile.is_open())
         {                   //READING UNTIL END OF FILE
             while(!Myfile.eof())
             {
                 getline(Myfile,line);       //CHECKIMG
                 if ((offset = line.find(search)) != string::npos)
                 {
                      flag = 1;
                 }
             }
             Myfile.close();
         }   //IF FILE IS NOT OPENED
         else
             cout<<"Unable to open this file."<<endl;
         }
         if(flag == 0)     //THROWING EXCEPTION
                 throw IllegalVoter();
    }
          //PERSON WILL CAST HIS/HER VOTE
void cast_vote()
{
         system("cls");
         cout<<"CAST YOUR VOTE:"<<endl;
         cout<<"1. PPP"<<endl;
         cout<<"2. PML"<<endl;
         cout<<"3. PTI"<<endl;
             
         cout<<"\nEnter Your Choice: ";
         cin>>choice;
                     //IF USER HAS VOTED FOR PPP
         if(choice == 1)
         {
              votes_count_ppp++;
              total_votes++;
         }           //IF USER HAS VOTED FOR PML
         else if(choice == 2)
         {
              votes_count_pml++;
              total_votes++;
         }           //IF USER HAS VOTED FOR PTI
         else if (choice == 3)
         {
              votes_count_pti++;
              total_votes++;
         }          //IF USER HAS ENTERED WRONG CHOICE
         else
         {
             system("cls");
             cout<<"Invalid Key."<<endl;
             cout<<"Press Any Key To Continue."<<endl;
             getch();
         }
}
     //DISPLYING RESULTS
void display()
{
         system("cls");
         cout<<"\n\n********************************************************************************";
         cout<<"Time = "<<hr<<" : "<<mn<<"\t\t\tDay = "<<day<<"\t\tLocation = "<<location<<endl;
         cout<<"\n********************************************************************************";
       
         cout<<"Total number of votes voted for:"<<endl<<endl;
         cout<<"\tPPP = "<<votes_count_ppp<<endl;
         cout<<"\tPML = "<<votes_count_pml<<endl;
         cout<<"\tPTI = "<<votes_count_pti<<endl<<endl;
         cout<<"\tTotal = "<<total_votes<<endl;
     }
};

int main()
{
PollingStation p;   //OBJECT OF POLLING STATION CLASS
    char another;       //VARIABLES
    string id;        
   
    p.start();          //CALLING THE FUNTION TO GET DATA
                       
    do{                 //LOOP UNTIL USER WANTS
        try{
              system("cls");   //USER WILL ENTER HIS/HER ID CARD NUMBER
              cout<<"Enter ID Card Number: ";
     cin>>id;
     p.checkdata(id);     //CHECKING
     p.cast_vote();       //CASTING VOTE(IF ILLEGIBLE)
           }
        catch(PollingStation::IllegalVoter)  //IF NOT ILLEGIBLE THEN
          {
              cout<<"NO ENTRY WITH THIS ID"<<endl;
              cout<<"Press any key to continue...";
              getch();
          }
         
        system("cls");         //ASKING USER WHETHER HE/SHE WANTS TO ENTER DATA
        cout<<"Enter another phone number(y/n)? ";
        another = getch();
      }while(another == 'Y' || another == 'y'); //LOOP TERMINATION CONDITION
   
   
    ofstream file;   //OPENING FILE FOR WRITTING
    file.open("POLLING_RESULTS.DAT", ios::binary);
    p.display();     //DISPLYING THE DATA & WRITTING TO THE FILE
    file.write(reinterpret_cast<char*>(&p),sizeof(p));  //SO THAT IT COULD BE DSPLAYED ANYTIME
    file.close();                                       //USER WANTS & THEN CLOSING THE FILE
   
    cout<<"\nFile Written"<<endl;
    cout<<"Press any key to exit"<<endl;
getch();
return 0;
}

Output

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Polymorphism example in c++ language

Problem

Implement the following given scenario, include two  constructors (no argument, with arguments), two functions getvalue(), and  displayvalue() for all classes.

Code

#include<iostream>
#include<conio.h>
#include<string>
using namespace std;

class Vehicle
{
      protected:
                int i;
                string s;
     
      public:
             Vehicle(): i(0), s("")
             {         }
             Vehicle(int a,string ss): i(a), s(ss)
             {           }
             void getdata()
             {
                  cout<<"Enter Vehicle Number: ";
                  cin>>i;
                  fflush(stdin);
                  cout<<"Enter vehicle name: ";
                  getline(cin, s);
             }
           
             void display()
             {
                  cout<<"Vehicle Number: "<<i;
                  cout<<"Vehicle Name: "<<s;
             }
};

class land_Vehicle : public Vehicle
{
      protected:
                int b;
                string s1;
     
      public:
             land_Vehicle(): b(0), s1("")
             {         }
             land_Vehicle(int a,string ss, int r, string s0): b(a), s1(ss), Vehicle(r,s0)
             {           }
             void getdata()
             {
                  Vehicle :: getdata();
                  cout<<"Enter Land Vehicle Number: ";
                  cin>>b;
                  fflush(stdin);
                  cout<<"Enter Land vehicle name: ";
                  getline(cin, s1);
             }
           
             void display()
             {
                  Vehicle :: display();
                  cout<<"Vehicle Number: "<<b;
                  cout<<"Vehicle Name: "<<s1;
             }
};

class Boat : public Vehicle
{
      protected:
                int c;
                string s2;
     
      public:
             Boat(): c(0), s2("")
             {         }
             Boat(int a,string ss, int r, string s0): c(a), s2(ss), Vehicle(r,s0)
             {           }
             void getdata()
             {
                  Vehicle :: getdata();
                  cout<<"Enter Boat Number: ";
                  cin>>c;
                  fflush(stdin);
                  cout<<"Enter Boat name: ";
                  getline(cin, s2);
             }
           
             void display()
             {
                  Vehicle :: display();
                  cout<<"Vehicle Number: "<<c;
                  cout<<"Vehicle Name: "<<s2;
             }
};

class aircraft : public Vehicle
{
      protected:
                int d;
                string s3;
     
      public:
             aircraft(): d(0), s3("")
             {         }
             aircraft(int a,string ss, int r, string s0): d(a), s3(ss), Vehicle(r,s0)
             {           }
             void getdata()
             {
                  Vehicle :: getdata();
                  cout<<"Enter Aircraft Number: ";
                  cin>>d;
                  fflush(stdin);
                  cout<<"Enter Aircarft name: ";
                  getline(cin, s3);
             }
           
             void display()
             {
                  Vehicle :: display();
                  cout<<"Vehicle Number: "<<d;
                  cout<<"Vehicle Name: "<<s3;
             }
};

class car : public land_Vehicle
{
      protected:
                int e;
                string s4;
     
      public:
             car(): e(0), s4("")
             {         }
             car(int a,string ss, int q1, string q2,int q3,string q4): e(a), s4(ss),land_Vehicle(q1,q2,q3,q4)
             {
             }
             void getdata()
             {
                  land_Vehicle :: getdata();
                  cout<<"Enter car Number: ";
                  cin>>e;
                  fflush(stdin);
                  cout<<"Enter car name: ";
                  getline(cin, s4);
             }
           
             void display()
             {
                  land_Vehicle :: display();
                  cout<<"Vehicle Number: "<<e;
                  cout<<"Vehicle Name: "<<s4;
             }
};

class truck  : public land_Vehicle
{
      protected:
                int f;
                string s5;
     
      public:
             truck(): f(0), s5("")
             {         }
             truck(int a,string ss, int q, string qq,int q3,string q4): f(a), s5(ss),land_Vehicle(q,qq,q3,q4)
             {           }
             void getdata()
             {
                  land_Vehicle :: getdata();
                  cout<<"Enter truck Number: ";
                  cin>>f;
                  fflush(stdin);
                  cout<<"Enter truck name: ";
                  getline(cin, s5);
             }
           
             void display()
             {
                  land_Vehicle :: display();
                  cout<<"Vehicle Number: "<<f;
                  cout<<"Vehicle Name: "<<s5;
             }
};

class sports_car  : public car
{
      protected:
                int g;
                string s6;
     
      public:
             sports_car(): g(0), s6("")
             {         }
           
             sports_car(int a,string ss, int q, string qq,int q3,string q4,int q5,string q6): g(a), s6(ss),car(q,qq,q3,q4,q5,q6)
             {           }
             void getdata()
             {
                  car:: getdata();
                  cout<<"Enter sports car Number: ";
                  cin>>g;
                  fflush(stdin);
                  cout<<"Enter sports car name: ";
                  getline(cin, s6);
             }
           
             void display()
             {
                  car:: display();
                  cout<<"Vehicle Number: "<<g;
                  cout<<"Vehicle Name: "<<s6;
             }
};

class yacht  : public Boat
{
      protected:
                int h;
                string s7;
     
      public:
             yacht(): h(0), s7("")
             {         }
             yacht(int a,string ss, int q, string qq,int q3,string q4): h(a), s7(ss),Boat(q,qq,q3,q4)
             {           }
             void getdata()
             {
                  Boat::getdata();
                  cout<<"Enter yacht Number: ";
                  cin>>h;
                  fflush(stdin);
                  cout<<"Enter yacht name: ";
                  getline(cin, s7);
             }
           
             void display()
             {
                  Boat :: display();
                  cout<<"Vehicle Number: "<<h;
                  cout<<"Vehicle Name: "<<s7;
             }
};

class sail_boat  : public Boat
{
      protected:
                int k;
                string s8;
     
      public:
             sail_boat(): k(0), s8("")
             {         }
             sail_boat(int a,string ss, int q, string qq,int q3,string q4): k(a), s8(ss),Boat(q,qq,q3,q4)
             {           }
             void getdata()
             {
                  Boat :: getdata();
                  cout<<"Enter sail_boat Number: ";
                  cin>>k;
                  fflush(stdin);
                  cout<<"Enter sail_boat name: ";
                  getline(cin, s8);
             }
           
             void display()
             {
                  Boat :: display();
                  cout<<"Vehicle Number: "<<k;
                  cout<<"Vehicle Name: "<<s8;
             }
};

class f16 : public aircraft
{
       protected:
                int j;
                string s9;
     
      public:
             f16(): j(0), s9("")
             {         }
             f16(int a,string ss, int q, string qq,int q3,string q4): j(a), s9(ss), aircraft(q,qq,q3,q4)
             {           }
             void getdata()
             {
                  aircraft :: getdata();
                  cout<<"Enter f16 Number: ";
                  cin>>j;fflush(stdin);
                  cout<<"Enter f16 model: ";
                  getline(cin, s9);
             }
           
             void display()
             {
                  aircraft :: display();
                  cout<<"f16 Number: "<<j;
                  cout<<"f16 model: "<<s9;
             }
};

class helicopter  : public aircraft
{
      protected:
                int l;
                string s10;
     
      public:
             helicopter(): l(0), s10("")
             {         }
             helicopter(int a,string ss, int q, string qq,int q3,string q4): l(a), s10(ss),aircraft(q,qq,q3,q4)
             {           }
             void getdata()
             {
                  aircraft :: getdata();
                  cout<<"Enter helicopter Number: ";
                  cin>>l;
                  cout<<"Enter helicopter model: ";
                  getline(cin, s10);
             }
           
             void display()
             {
                  aircraft :: display();
                  cout<<"helicopter Number: "<<l;
                  cout<<"helicopter model: "<<s10;
             }
};

int main()
{
    aircraft a;
    a.getdata();
    a.display();
   
    Boat b;
    b.getdata();
    b.display();
   
    land_Vehicle l;
    l.getdata();
    l.display();
   
    car c;
    c.getdata();
    c.display();
   
    truck t;
    t.getdata();
    t.display();
   
    sports_car sp;
    sp.getdata();
    sp.display();
   
    yacht y;
    y.getdata();
    y.display();
   
    sail_boat s;
    s.getdata();
    s.display();
   
    f16 f;
    f.getdata();
    f.display();
   
    helicopter h;
    h.getdata();
    h.display();
   
    cout<<"Press any key exit.";
    getch();
    return 0;
}

Output

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