File Handling

#include<iostream.h>

#include<conio.h>

#include<iomanip.h>

#include<fstream.h>

#include<stdlib.h>

void main()

 {

clrscr();

ofstream out;

ifstream in;

char ch,fname1[10],fname2[10];

cout<<"Enter the file name to be copied:";

cin>>fname1;

cout<<"Enter the new file name:";

cin>>fname2;

out.open(fname1);

out<<"This is a test program.";

out.close();

in.open(fname1);

if(in.fail())

       {

cerr<<"No such a file exists.";

getch();

exit(1);

       }

out.open(fname2);

if(out.fail())

       {

cerr<<"Unable to create the file.";

exit(1);

getch();

       }

while(!in.eof())

       {

ch=(char)in.get();

out.put(ch);

       }

in.close();

out.close();

cout<<"The file is copied.\n";

in.open(fname2);

cout<<"The copied contents are:";

while(!in.eof())

 {

ch=(char)in.get();

cout<<ch;

 }

in.close();

getch();

 }

Multiple Inheritance

#include<iostream.h>

#include<constream.h>

class A { protected : int a;};

class B { protected : int b;};

class C { protected : int c;};

class D { protected : int d;};

class E : public A,B,C,D

 {

 int e;

public:

 void getdata()

  {

cout<<"\n Enter values of a,b,c,d,e:\n";

cin>>a>>b>>c>>d>>e;

  }

 void showdata()

  {

cout<<"\n a="<<a<<"\n b="<<b<<"\n c="<<c<<"\n d="<<d;               cout<<"\n e="<<e;

  }

 };

void main()

 {

clrscr();

E X;

X.getdata();

X.showdata();

getch();

 }

Multilevel Inheritance

#include<iostream.h>

#include<constream.h>

class A1

 {

protected:

     char name[15];

     int age;

 };

class A2: public A1

 {

protected:

float height;

float weight;

 };

class A3: public A2

 {

protected:

char sex;

public:

void get()

 {

cout<<"name :";

cin>>name;

cout<<"age :"; cin>>age;

cout<<"sex :"; cin>>sex;

cout<<"height :"; cin>>height;

cout<<"weight :"; cin>>weight;

 }

void show()

 {

cout<<"\n Name :"<<name;

cout<<"\Age :"<<age<<"years";

cout<<"\Sex :"<<sex;

cout<<"\Height :"<<height<<"feets";

cout<<"\Weight :"<<weight<<"kg.";

 }

 };

void main()

 {

clrscr();

A3 X;

X.get();

X.show();

getch();

 }

Single Inheritance

#include<iostream.h>

#include<constream.h>

class ABC

 {

protected:

     char name[15];

          int age;

 };

class abc: public ABC

 {

Protected:

     float height;

     float weight;

public:

  void getdata()

   {

cout<<"\n Enter Name and Age:";

cin>>name>>age;

cout<<"\n Enter Height and Weight:";

cin>>height>>weight;

   }

  void show()

   {

cout<<"\n Name:"<<name<<"\n Age:"<<age<<"years";

cout<<"\n Height:"<<height<<"feets";    

cout<<”\n weight:"<<weight<<"kg";

   }

 };

void main()

 {

clrscr();

abc x;

x.getdata();

x.show();

getch();

 }