Using a existing text file and edi and save

[patriic48]

How can I use my saved list to add new information in it and save it again?

I can´t find any information on how to do.

  // Phonebook

/* Use this to create small registers of users in projects*/

#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
#include <fstream>
#include <sstream>

using namespace std;

class Phonebook
{
public:
	Phonebook() : name(""), number(0) {}
	Phonebook(const string &_name, int _number) : name(_name), number(_number) {}
	Phonebook(const Phonebook &rhs) : name(rhs.name), number(rhs.number) {}
	Phonebook operator=(const Phonebook &rhs)
	{
		if (&rhs == this)
		{
			return *this;
		}
		
		name = rhs.name;
		number = rhs.number;
		return *this;
		
	}
	
	//Metod: Sets the necessary info
	void SetInfo(const string &_name, int _number)
	{
		name = _name;
		number = _number;
	}
	
	const string &Name() const { return name; }
	int Number() const { return number; }

	private:
	string name;
	int number;
};

//Function Declarations
void fillPhonebook(vector<Phonebook>&myPhonebook);
//fillVector
//@param vector<Class>)& - the vector to be filled


//Function Declarations
void bubbleSort(vector<Phonebook>&myPhonebook);
// BubbleSort - Sorts vector
// @param myList - The vector to be sorted

void swap(Phonebook &p, Phonebook &q);
// Swap - Creates temporary variables for swapping Names

int i = 0;
int deleteFromVector;

int main()
{
	vector<Phonebook>myPhonebook;
	
	while(true)
	{
		cout << " - Press 0 for info about Phonebook Application" << endl;
		cout << " - Press 1 to add a person and number" << endl;
		cout << " - Press 2 to print list" << endl;
		cout << " - Press 3 to delete person and number" << endl;
		cout << " - Press 4 to save list" << endl;
		cout << " - Press 5 to load and print list" << endl;
		cout << " - Press 6 to quit" << endl;

		int choice;
		cin >> choice;

		cout << endl;
	
		switch(choice)
		{

			case 0:
			{
				cout << "******Information about Phonebook Application******\n" << endl;
				cout << "An application for small phonelists in projects\n" << endl;
				cout << "1 - Creates a new list and adds a person to it.\nYou can add new persons to this list by pressing 1.\n" << endl;
				cout << "2 - Prints list.\n" << endl;
				cout << "3 - Delete person from the list.\n" << endl;
				cout << "4 - Saves the list.\n" << endl;
				cout << "5 - Loads and print the old list from a file.\n" << endl;
				cout << "***************************************************\n" << endl;
			}
			break;

			case 1:
			{
				fillPhonebook(myPhonebook);
			}
			break;		
			case 2:
			{
				/* cout << "Print all names and numbers" << endl;
				printPhonebook(myPhonebook); */

				bubbleSort(myPhonebook);
				cout << "Sort order by age, youngest first:" << endl;
				for (unsigned int i = 0; i < myPhonebook.size(); i++)
				{
					cout << myPhonebook[i].Name() << " " << myPhonebook[i].Number() << endl;
				}

				cout << "\n" << endl;

				ofstream outFile;
					outFile.open("Phonebook.txt");
					for (unsigned int i = 0; i < myPhonebook.size(); i++)
					{
						outFile << myPhonebook[i].Name() << " " << myPhonebook[i].Number() << endl;
					}
					outFile.close();
			}
			break;		
			case 3:
			{
				int index;

				cout << "Which index do you want to delete? (1-10)" << endl;

				bubbleSort(myPhonebook);
				for (unsigned int i = 0; i < myPhonebook.size(); i++)
				{
					cout << i << " " << myPhonebook[i].Name() << " " << myPhonebook[i].Number() << endl;
				}

				cin >> index; 

				cout << "\n";

				myPhonebook.erase(myPhonebook.begin() + index);
      		}
			break;
			case 4:
			{
				ofstream outFile;
				outFile.open("Phonebook.txt");
				for (unsigned int i = 0; i < myPhonebook.size(); i++)
				{
					outFile << myPhonebook[i].Name() << " " << myPhonebook[i].Number() << endl;
				}
				outFile.close();
			}
			break;
			case 5:
			{
				string line;

				ifstream inFile ("Phonebook.txt");
				if (inFile.is_open())
				{
					while (getline (inFile,line) )
					{
						cout << line << '\n';
					}

					inFile.close();
				}
				else cout << "Unable to open file"; 
			}
			break;
		}
		if(choice==6)
			break;
	}

	return 0;
}

// Function Definitions
void fillPhonebook(vector<Phonebook>&myPhonebook)
{
		string name;
		int number;					

		// Flush makes sure that the buffer is cleared and the characters are written to their destination
		cout << "Enter persons name: " << flush << endl;
		
		// Enter values into vector
		cin >> name;
			
		cout << "Enter persons number: " << flush << endl;
		
		// Enter values into vector
		cin >> number;

		/*Phonebook Phonebook(name, number);
		myPhonebook.push_back(Phonebook);*/

		myPhonebook.push_back(Phonebook(name, number));

		cout << endl;

		
			
}

void bubbleSort(vector<Phonebook>&myPhonebook)
{
	// The outer loop, going through all list
    for(unsigned int i = 0; i < myPhonebook.size(); i++)
	{
		//Inner loop, going through element by element
		int nrLeft = myPhonebook.size() - i; // To se how many has been gone through
		for (int j = 0; j < nrLeft - 1; j++)
		{
			
			if (myPhonebook[j].Name() > myPhonebook[j+1].Name()) // Compare the elements
			{
				swap(myPhonebook[j], myPhonebook[j+1]); 
			}
		}
	}
}

void swap(Phonebook &p, Phonebook &q) 
{ 
	Phonebook temp = p; 
	p = q;
	q = temp;
}

[Momothegreat]

My quick suggestion is not closing the output file until the end of the program.
But that seems to easy and probably won't work.