Sum of specific integers in .txt file

[cnb91]

Hi!
I haven't done a lot of coding before, but now I'm working on this budget/accounting-program. My first goal is to develop a program were the user puts in an amount of money they have spent and which category it's in (food, rent, clothes, etc). This information will then be stored in a .txt file. An example of how I want it to look like:

Food 500
Rent 1000
Clothes 300

Where the number represents the sum of all the amounts of money spent in that category that month. And this is where I'm stuck - how do I sum all these inputs (and ofcourse keep the categories divided)?

The way I work: I start reading from the file, and loads the whole file into a vector, using push_back. When the user is done with their input, the vector is then loaded back to the file. The category is a string, and the amount and the sum is integers.

Any tips? Is it better to change the file directly, or use arrays instead of a vector?

[CodeWriter]

Show us your code so far ...

[cnb91]

//main.cpp:
#include <iostream>
#include <string>
#include "Month.h"
#include "MonthManager.h"

MonthManager monthManager;
Month month;

using namespace std; 

void menu();

int main ()
{
	menu();
}

void menu()
{
	int n = 0;
	while (n < 3) //Just to run it some times
	{
		cout << "1. Expence " << endl << "2. Income" << endl;
		int choice; 
		cin >> choice; 

		if (choice == 1)
		{
			int amount, sum; string category;
			cout << "What category is the expence in?" << endl; 
			cin >> category; 
			cout << "How much did it cost?" << endl; 
			cin >> amount;
			//Some code for declearing the sum is needed here
			monthManager.addExpense(category, amount, sum); 
		}

		if (choice == 2)
			//Not started yet
		
		n++;
	}

}

//Month.h:
#pragma once
#include <string>

class Month
{
public:
	Month(void);
	~Month(void);

	Month(std::string category, int amount, int sum);
	std::string getCategory();
	int getAmount();
	int getSum();

private: 
	std::string _category; 
	int _amount;
	int _sum;
};

//Month.cpp:
#include "Month.h"
#include "MonthManager.h"
#include <string>
#include <vector>

using namespace std;

MonthManager monthManager;

Month::Month(void)
{
	_category = "Hi";
	_amount = 0; 
	_sum = 0; 
}


Month::~Month(void)
{
}

Month::Month(string category, int amount, int sum)
{
	_category = category; 
	_amount = amount; 
	_sum = sum;
}


string Month::getCategory()
{
	return _category;
}

int Month::getAmount()
{
	return _amount;
}

int Month::getSum()
{
return _sum;
}

//MonthManager.h:
#pragma once
#include <vector>
#include <string>
#include "Month.h"

class MonthManager
{
public:
	MonthManager(void);
	~MonthManager(void);
	void addExpense (std::string category, int amount, int sum);


private: 
	void readFromFile();
	void saveToFile();
	std::vector<Month> _tmpMonth;
};



//MonthManager.cpp: 
#include "MonthManager.h"
#include <fstream>
#include <iostream>
#include <string>
#include <vector>
using namespace std; 


MonthManager::MonthManager(void)
{
	readFromFile();
}


MonthManager::~MonthManager(void)
{
}

void MonthManager::readFromFile()					
{								
}

void MonthManager::saveToFile()			//Haven't done these two functions yet				
{
}

void MonthManager::addExpense(string category, int amount, int sum)	
{
	readFromFile();
	for (int i = 0; i < _tmpMonth.size(); i++)
	{
		if (_tmpMonth[i].getCategory() == category)
		{
			sum += amount;
			Month temp(category, amount, sum);
			_tmpMonth.push_back(temp);
		}


	}

	saveToFile();
}

[CodeWriter]

Surprised no one has responded yet as it doesn't seem a hard problem in itself. Unfortunately I am in the beginner c++ category and know nothing yet about vectors or push_back. I have done similar things in plain old c but that is not what you need. I don't even know how to deal with multiple files yet.

[cnb91]

Anyone? :)