This is my function to get lines from file to strings

void getStringsFromFile() {
    ifstream database;
    database.open("Database.txt", ios::app | ios::in | ios::binary);

    if (!database) {
        cout << "Kunne ikke indlaese filen..." << endl;
    }
    int count = 0, c = 0;
    string getString, tmp, str[256];
    for (int i = 0; i < 5; i  ) {
        while (getline(database, getString)) {
            str[i] = getString;
            cout << "String: [" << count   << "] " << str[i] << endl;
        }
    }
    sortStrings(getString);
}

This is how I'm saving my data to .txt file

     if (database.is_open()) {
         database << list[i].navn << "\t" << list[i].addresse << "\t" << list[i].alder << "\t" << list[i].tlf << "\t" << "\n";
         database.close();

It outputs like this: line 0 is empty

Kasper Jensen   
Jomfrugade 5    21  44556677

Victor Hansen   
Østergade 94    25  54644773

I have this function to sort the strings, ascending by insertion. It don't work with string to char

void sortStrings(string &lines) {
    string* lines = nullptr;
    string temp;
    int count;

    for (int i = 0; i < count - 1; i  ) {
        for (int j = 0; j >= 0; j--) {
            if (lines[j] > lines[j   1]) {
                temp = lines[j];
                lines[j] = lines[j   1];
                lines[j   1] = temp;
            }
        }
    }
}

I want my code to grab relevant lines from one .txt file and sort it to another. I dont really care which sorting method

I have problems with it recognizing the right strings and grabbing them and outputting them into new file

CodePudding user response：

The getStringsFromFile function will read all lines from the file, and put them all into str[0]. Then the sortStrings function will attempt to sort a single string. There are other things that looks weird as well.

What I recommend you to do, is to create a vector of strings, read lines in a loop (the while (getline(...)) loop) and add to the vector, then use the standard std::sort function to sort the vector.

Once that's done you can write the strings in the vector to a new file.

Note that the above assume that there's no specific format in the file, that each line is its separate record. If your file have a specific multi-line record format then that won't work.

If this is the case then I recommend you create a class for the records, implement a stream extract operator for the class (operator>> for std::istream), and use a loop (while (file >> my_record_object)) to read all records into a vector.

Then again sort the vector using std::sort, using a suitable ordering function (lambda or overloaded operator< function for the class). Then write the data in the vector to the new file using an overloaded operator<< function.