C++ reading data from a *.txt file to vector of struct

Question

I'm new one in C++ and have some misunderstandings about file read/write...

I have a .txt data file that contains information about the streets ie street, home number and number of flats

I have a task to read data from a file, add new one, delete unwanted and make some calculations about the number of flats on certain street

For data storage during the program work I made a vector of struct:

struct homeAdressBook {
    std::string street;
    char homeNumber[255];
    int flats;
};

std::vector<homeAdressBook> HAB;

Program code is below:

std::fstream document;
    document.open("name.txt");
    if (!document) {
        std::ofstream document;
        document.open("name.txt");
    }
    if (!document)
        std::cout << "File open error" << std::endl;
    else {
//Here (while loop) I want to read data from a file and add to my vector of struct for further usage, it partly works somehow but this point is unclear for me
        while (!document.eof()) {
            HAB.push_back(homeAdressBook());
            std::getline(document, HAB[i].street);
            document >> HAB[i].street;
            document >> HAB[i].homeNumber;
            document >> HAB[i].flats;
            i++;
        }
        document.close();
        do {
            switch (menu()) {
            case 0: {
                document.close();
                exit = false;
                break;
            }
//Here (case 1) I add new data and write it in file, here I have no problems at the moment
            case 1: {
                document.open("name.txt", std::ios::app);
                HAB.push_back(homeAdressBook());
                std::cin.ignore();
                std::cout << "Enter the address: ";
                std::getline(std::cin, HAB[i].street);
                std::cout << "Enter home number: ";
                std::cin.getline(HAB[i].homeNumber, 255);
                std::cout << "Enter number of flats: ";
                std::cin >> HAB[i].flats;
                document << HAB[i].street << HAB[i].homeNumber << HAB[i].flats << std::endl;
                document.close();
                i++;
                break;
            }
//Here (case 2) I want to read data from a file, it reads data except first line of data
            case 2: {
                int total = i;
                std::cout << std::setw(20) << "Street" << std::setw(20) << "Home Number" << std::setw(20) << "Number of flats" << std::endl;
                document.open("name.txt", std::ios::in);
                for (int j = 0; j < total; j++) {
                    std::cout << std::setw(20) << HAB[j].street << std::setw(20) << HAB[j].homeNumber << std::setw(20) << HAB[j].flats << std::endl;
                }
                document.close();
                break;
            }
//Here (case 3) data should be deleted from a file if necessary
            case 3: {
                document.open("name.txt", std::ios::out | std::ios::in);
                int strDelete = 0;
                std::cout << "0. Exit to main menu" << std::endl;
                for (i = 0; i < HAB.size(); i++) {
                    std::cout << i + 1 << ". " << HAB[i].street << std::endl;
                }
                std::cout << "\nType number of street to delete: ";
                std::cin >> strDelete;
                if (strDelete)
                    i--;
                else break;
                HAB.erase(HAB.begin() + (strDelete - 1));
                document.close();
                break;
            }
            }
        } while (exit);
    }
    system("pause");
    return 0;
}

Data in .txt file is written like this:

aaa street 10 50
aaa street 10 45
bbb street 1 10
ccc street 1 12
ccc street 1/10 25

Each line in .txt file belongs to [i]-s vector of struct elements I cannot understand how correctly add data from a .txt file to my vector of structs during the program work (name of the street can hold up to 5 or 6 words and how program can separate whether it is the name of the street or it is home number or number of flats)

Answer 1

I recommend that you overload operator>> for your structure:

struct homeAdressBook
{
    std::string column1;
    std::string street;
    std::string homeAddress;
    int flats;
    friend std::istream& operator>>(std::istream& input, homeAddressBook& address);
};

std::istream& operator>>(std::istream& input, homeAddressBook& address)
{
  input >> address.column1;
  input >> address.street;
  input >> address.homeAddress;
  input >> address.flats;
  return input;
}

The above will allow you to change your input process to:

std::vector<homeAddressBook> database;
homeAddressBook record;
//...
std::ifstream data_file("addresses.txt");
while (data_file >> record)
{
  database.push_back(record);
}

Notes

1. Your post describes 3 columns in the data, but your data source shows 4.
2. You open your document as an output stream ( ostream ) and you use getline on the output stream.
3. Your structure name has "book" which implies a collection of items. I recommend using a name such as "Home_Address" to indicate a single item. Use std::vector for the book.

Edit 1:
Prefixed members in operator>> with "address.".