Addressbook writing to file

Question

I have an Addressbook C++ program that compiles and everything, but I cannot figure out how to write it to a file that saves the data each time it exits. Here is my code:

 //AddressBook Program
#include <iostream>
#include <string.h>
#include <cstdlib>
#include <stdio.h>                                                                

using namespace std;

class AddressBook{

public :
   AddressBook()
      {
         count = 0;
      }

   void AddEntry();
   void DisplayAll();
   void DisplayEntry(int i); // Displays one entry                                   
   void SearchEntry();

   int MainMenu();

   struct Entry_Struct
   {
      char firstName[ 15 ] ;
      char lastName[ 15 ] ;
      char birthday[ 15 ] ;
      char phone[ 15 ] ;
      char email[ 15 ] ;
   };

   Entry_Struct entries[100];
   unsigned int count;
};


void AddressBook::AddEntry()
{
   cout << "Entry number " << (count + 1) << " : " << endl;

   cout << "Enter First Name: ";
   cin >> entries[count].firstName;

   cout << "Enter Last Name: ";
   cin >> entries[count].lastName;

   cout << "Enter Date of Birth: ";
   cin >> entries[count].birthday;

cout << "Enter Phone Number: ";
   cin >> entries[count].phone;

   cout << "Enter Email: ";
   cin >> entries[count].email;

   ++count; // tally total entry count                                               
}


void AddressBook::DisplayEntry(int i)
{
   cout << "Entry[" << i + 1 << "] : " << endl; // states # of entry                 
   cout << "First name : " << entries[i].firstName << endl;
   cout << "Last name : " << entries[i].lastName << endl;
   cout << "Date of birth : " << entries[i].birthday << endl;
   cout << "Phone number : " << entries[i].phone << endl;
   cout << "Email: " << entries[i].email << endl;
}

void AddressBook::DisplayAll()
{
   cout << "Number of entries : " << count << endl;

   for(int i = 0;i < count;++i)
      DisplayEntry(i);
}

void AddressBook::SearchEntry()
{
   char lastname[32];
   cout << "Enter last name : ";
   cin >> lastname;

   for(int i = 0;i < count;++i)
   {
      if(strcmp(lastname, entries[i].lastName) == 0)
      {
         cout << "Found ";
         DisplayEntry(i);
         cout << endl;
      }
   }
}


// Your class                                                                        
AddressBook my_book;

int MainMenu()
{
   int num;
   bool bQuit = false;

   // Put all your code into a while loop.                                           
   while(bQuit == false)
   {                                              

      cout << "+-------------------------------------+" << endl;
      cout << "|         Address Book Menu           |" << endl;
      cout << "|                                     |" << endl;
      cout << "| 1- Add an entry                     |" << endl;
      cout << "| 2- Search for an entry by last name |" << endl;
      cout << "| 3- Display all entries              |" << endl;
      cout << "| 4- Exit                             |" << endl;
      cout << "|                                     |" << endl;
      cout << "+-------------------------------------+" << endl;

      cout << endl;
      cout << "Please enter a number for one of the above options: ";
      cin >> num;
      cout << endl;

      if (num == 1)
         my_book.AddEntry();
      else if (num == 2)
         my_book.SearchEntry();
      else if (num == 3)
         my_book.DisplayAll();
      else if (num == 4)
         bQuit = true;
      else
         cout << "Invalid choice. Please try again" << endl;

      cout << endl;                                                            
   }

   return 0;
}

int main (){
   MainMenu();
   return 0;
}

I've gone over my textbook all day and nothing I'm doing is working.

Do you want to read/write to an addressbook file? Then you should look up ostream, istream, and open. — ChuckCottrill, Oct 30 '13 at 01:14

score 0 · Answer 1 · answered Oct 30 '13 at 01:16

Here is a basic example of opening, and writing an output file,

// basic file operations
#include <iostream>
#include <fstream>
using namespace std;

int main () {
  ofstream outfile;
  outfile.open ("addressbook.txt");
  outfile << "Daffy,Duck,123 Main Street,Anytown,OH,USA,123-456-7890\n";
  myfile.close();
  return 0;
}

score 0 · Answer 2 · answered Oct 30 '13 at 01:18

You need to have an inserter for your class. It's done using operator <<:

// Inside your class:
friend std::istream& operator<<(std::ostream& os, const AddressBook ab)
{
    return os << /* ... */
}

As you can see, a user-defined operator << can be implemented in terms of the pre-defined standard inserter. You can use it in the following way:

std::ifstream in("yourtxtfile.txt");
in << my_book;

Addressbook writing to file

2 Answers2