C++ program to learn the basics of using a file

This is a program that would help you to learn about the basics of a file through c++. This would teach ue that how can we acess a file, of how can we open it, how can we cloase it, how can we acess the documents present in a file. Its easy to use just install a c++ compiler copy this program to a new notepad and save it as a .cpp file and copy it in the bin of c++ compiler. Its all done now just open compiler search for the file open it and run it.

#include<stdlib.h>
#include<conio.h>
#include<fstream.h>
#include<ctype.h>
void main()
{   clrscr();
    fstream f1("mydata.dat",ios::in);
    char ch;
    int cnt=0;
    char c;
    if(!f1)
    {  cout<<"\n cannot open";
       getch();
       exit(-1);
    }
    cout<<"\n the text document is :";
    while (!f1.eof())
    {  f1.get(c);
       cout<<c;
    }
    f1.close();
    f1.open("mydata.dat",ios::in);
    while (!f1.eof())
    {  f1.get(ch);
       if(isalpha(ch))
       cnt++;
    }
    cout<<"\n number of alphabets are:"<<cnt;
    f1.close();
    getch();
}