Contact Book in C++ using File Handling

Straightaway prior brushing up knowledge of the language and file handling is required. So let us do discuss C++ Language concepts in File Handling and loops. Straight we know that for compiling the code, an IDE for compiling C++ language is required such as Code Block, Visual Studio Code, Dev C++, etc is required to run our program.

This software aims to cream a contact book in C++ using File Handling. In C++, files are mainly dealt with by using three classes fstream, ifstream, ofstream available in the fstream header file.

• ofstream: Stream class to write on files
• ifstream: Stream class to read from files
• fstream: Stream class to both read and write from/to files.

Implementation: 

The contacts will be saved to a file. Contact Book will be providing the following features to the user:

1. Add contact.
2. Search Contact.
3. Help.
4. Exit.

Details of contact that will be saved are as follows:

1. First name.
2. Last name.
3. Phone Number.

Example

C++

// Importing input output operations file
#include <iostream>
// Importing file class
#include <fstream>
// Importing standard library file
#include <stdlib.h>

using namespace std;

// Variables declared outside any function
// hence scope is global, hence global variables
string fname, lname, phone_num;

// Methods

// Helper Methods followed by
// Main driver method

void addContact();
void searchContact();
void help();
void self_exit();
bool check_digits(string);
bool check_numbers(string);

// Method 1
// Helper method
void self_exit()
{
    system("cls");
    cout << "\n\n\n\t\tThank You for using Contact-Saver!";
    exit(1);
}

// Method 2
// Helper method
void help()
{
    cout << "Help Center";
    cout << endl << endl;
    system("pause");
    system("cls");
}

// Method 3
// Helper method
void addContact()
{
    ofstream phone("number.txt", ios::app);
    system("cls");
    cout << "\n\n\tEnter First Name : ";
    cin >> fname;
    cout << "\n\tEnter Last Name : ";
    cin >> lname;
    cout << "\n\tEnter Phone Number : ";
    cin >> phone_num;

    if (check_digits(phone_num) == true) {
        if (check_numbers(phone_num) == true) {
            if (phone.is_open()) {
                phone << fname << " " << lname << " "
                      << phone_num << endl;
                cout << "\n\tContact saved successfully !";
            }
            else {
                cout << "\n\tError in opening record!";
            }
        }
        else {
            cout << "\n\tOnly numbers are allowed!";
        }
    }
    else {
        cout << "\n\tPhone number should be of 10 digits "
                "only.";
    }
    cout << endl << endl;
    system("pause");
    system("cls");
    phone.close();
}

// Method 4
// Helper method
void searchContact()
{
    bool found = false;
    ifstream myfile("number.txt");
    string keyword;
    cout << "\n\tEnter Name to search : ";
    cin >> keyword;
    while (myfile >> fname >> lname >> phone_num) {
        if (keyword == fname || keyword == lname) {
            system("cls");
            cout << "\n\n\n\t\tCONTACT DETAILS";
            cout << "\n\nFirst Name : " << fname;
            cout << "\nLast Name : " << lname;
            cout << "\nPhone Number : " << phone_num;
            found = true;
            break;
        }
    }
    if (found == false)
        cout << "\nNo such contact is found!";

    cout << endl << endl;
    system("pause");
    system("cls");
}

// Method 5
// Helper method
bool check_digits(string x)
{
    if (x.length() == 10)
        return true;
    else
        return false;
}

// Method 6
// Helper method
bool check_numbers(string x)
{
    bool check = true;

    for (int i = 0; i < x.length(); i++) {
        if (!(int(x[i]) >= 48 && int(x[i]) <= 57)) {
            check = false;
            break;
        }
    }

    if (check == true)
        return true;

    if (check == false)
        return false;

    cout << endl << endl;
    system("pause");
    system("cls");
}

// Method 7
// Main driver method
int main()
{
    int choice;
    system("cls");
    system("color 0A");
    while (1) {
        cout << "\n\n\n\t\t\tCONTACT SAVER";
        cout << "\n\n\t1. Add Contact\n\t2. Search "
                "Contact\n\t3. Help\n\t4. Exit\n\t> ";
        cin >> choice;

        // Switch case
        switch (choice) {
        case 1:
            addContact();
            break;

        case 2:
            searchContact();
            break;

        case 3:
            help();
            break;

        case 4:
            self_exit();
            break;

        default:
            cout << "\n\n\tInvalid Input!";
        }
    }
    return 0;
}

Output