Thread: Data File problem

Hello everybody.
I am having problems with this program:

Code:

#include <iostream>
#include <fstream>
using namespace std;

class Date
{
private:
	int month;
	int day;
	int year;
	static char slash;
public:
	void setDate();
	void showDate();
	void setMonth();
	void setDay();
	void setYear();
};
char Date::slash = '/';
void Date::setDate()
{
	cin  >> month;
	cin.get();
	cin  >> day;
	cin.get();
	cin  >> year;
	cin.get();
}
void Date::setMonth()
{
	if(month > 12 || month == 0)
		month = 12;
	else
		month = month;			
}
void Date::setDay()
{
	if(day > 31 || day == 0)
		day = 31;
	else
		day = day;
}
void Date::setYear()
{
	if(year <= 999 || year > 2500)
		year = 2007;
	else
		year = year;						
}
void Date::showDate()
{
	cout << month << slash << day << slash << year << endl;	
}
void main()
{
	Date aDate[5];
        cout << "Please enter five dates." << endl;
	cout << "You cant enter any slashes(/), only numbers(12 3 2007)" << endl;
	ofstream out("H:\\Dates.txt");
	for(int x = 0; x < 5; ++x)
	{
	    aDate[x].setDate();
	    aDate[x].setMonth();
	    aDate[x].setDay();
	    aDate[x].setYear();
	    out.write((char*)(&aDate[x]), sizeof(aDate[x]));
	} // end of for
	cout << endl << "The dates you entered were: " << endl << endl;
	for(int x = 0; x < 5; ++x)
		aDate[x].showDate();
	cout << endl;
	system("pause");
}

The program has to accept 5 dates that the user inputs..
Like this:
12 3 1987
11 4 2000
And so on. then the program outputs the dates entered whit slashes like this:
12/3/1987
11/4/2000

The problem is that I want to save the dates entered in a .txt file. I've done this before but never with objects. Since the data objects are type int and I think that I need to use the write() function, that only accept chars.
I need to save the dates without the slashes and then open the document's data in he program, I think I need the read() function but I cant even save what I want in the first place.
So whats wrong with my code?
Thanks to everyone for their time.

Well, I think you have two options. Either declare the day/month/year as chars or strings, or convert your ints after checking them for proper bounds. You can always use atoi() if you use chars. Just a thought to make it easier for what you'd like to do.

The easiest way to write your data to the file is thus:

out << aDate[x].setMonth();

and so on.

Hope this helps

What do you mean "it doesn't work to save the date"? Your code looks right to me. It may not be the most portable way to store data.

I also have some concern for the completeness of your error checking (e.g. only some months allow for 31 days, negative numbers are valid in an integer, but you only check for less or equal to zero, etc).

--
Mats

Well it looks good to me too, but it just wont save what I want!! and about my error checking, am aware of what you mentioned but thats what my professor asked for, so am not going to torture myself and check for all possible scenarios on entering a date. Its just a simple program to practice the use of static variables and saving to .txt file. But anyway thanks for your time, oh and what do you mean by:

It may not be the most portable way to store data.

I followed matsp and kcpilot's advice and changed my code to this:

Code:

#include <iostream>
#include <fstream>
using namespace std;

class Date
{
private:
	int month;
	int day;
	int year;
	static char slash;
public:
	void setDate();
	void showDate();
	void setMonth();
	void setDay();
	void setYear();
};
char Date::slash = '/';
void Date::setDate()
{
	cin  >> month;
	cin.get();
	cin  >> day;
	cin.get();
	cin  >> year;
	cin.get();
}
void Date::setMonth()
{
	if(month > 12 || month == 0)
		month = 12;
	else
		month = month;			
}
void Date::setDay()
{
	if(day > 31 || day == 0)
		day = 31;
	else
		day = day;
}
void Date::setYear()
{
	if(year <= 999 || year > 2500)
		year = 2007;
	else
		year = year;						
}
void Date::showDate()
{
	cout << month << slash << day << slash << year << endl;	
}
void main()
{
	Date aDate[5];
        cout << "Please enter five dates." << endl;
	cout << "You can enter any slashes(/), only numbers(12 3 2007)" << endl;
	ofstream out("H:\\Dates.txt");
	for(int x = 0; x < 5; ++x)
	{
            aDate[x].setDate();
	    aDate[x].setMonth();
	    aDate[x].setDay();
	    aDate[x].setYear();
	    out << aDate[x].month << aDate[x].day << aDate[x].year << endl;
	}
	cout << endl << "The dates you entered were: " << endl << endl;
	for(int x = 0; x < 5; ++x)
		aDate[x].showDate();
	cout << endl;
	system("pause");
}

But then it gives me this error:

Error 1 error C2248: 'Date::month' : cannot access private member declared in class 'Date' h:\documents\c++\oop\program7\program7\program7.cp p 66

Anyway... thanks!

If you have to convert an int to a char array look here, but you should just use the methods that suggest.

>> Error 1 error C2248: 'Date::month' : cannot access private member declared in class 'Date'

This tells you the problem. The code in main cannot access the private member called month. The fact that the member is private means that only member functions of the class can access it.

You need some get functions (like getMonth() and getDay()) and then call those to get the information from the class object.

Another solution that is probably better would be to overload operator<< to output the date and make that function a friend so it can access the data itself.

WTF?
Okay so I changed my code to this:

Code:

#include <iostream>
#include <fstream>
using namespace std;

class Date
{
private:
	int month;
	int day;
	int year;
	static char slash;
public:
	void setDate();
	void showDate();
	void setMonth();
	void setDay();
	void setYear();
};
char Date::slash = '/';
void Date::setDate()
{
	cin  >> month >> day >> year;	
}
void Date::setMonth()
{
	if(month > 12 || month == 0)
		month = 12;
	else
		month = month;			
}
void Date::setDay()
{
	if(day > 31 || day == 0)
		day = 31;
	else
		day = day;
}
void Date::setYear()
{
	if(year <= 999 || year > 2500)
		year = 2007;
	else
		year = year;						
}
void Date::showDate()
{
	cout << month << slash << day << slash << year << endl;	
}
void main()
{
	Date aDate[5];
        cout << "Please enter five dates." << endl;
	cout << "You can enter any slashes(/), only numbers(12 3 2007)" << endl;
	ofstream out("H:\\Dates.txt");
	for(int x = 0; x < 5; ++x)
	{
	    aDate[x].setDate();
	    aDate[x].setMonth();
	    aDate[x].setDay();
	    aDate[x].setYear();
	    out << aDate[x].month << " " << aDate[x].day << " ";
	    out << aDate[x].year << endl;
	}
	cout << endl << "The dates you entered were: " << endl << endl;
	for(int x = 0; x < 5; ++x)
		aDate[x].showDate();
	cout << endl;
	system("pause");
}

And it gives me 3 errors:

Error 1 error C2248: 'Date::month' : cannot access private member declared in class 'Date' h:\documents\c++\oop\program7\program7\program7.cp p 61
Error 2 error C2248: 'Date::day' : cannot access private member declared in class 'Date' h:\documents\c++\oop\program7\program7\program7.cp p 61
Error 3 error C2248: 'Date::year' : cannot access private member declared in class 'Date' h:\documents\c++\oop\program7\program7\program7.cp p 62

But it saves what I need in a .txt file. Why does it give me these errors... the program works perfectly!

The program didn't compile, so if you are running something and it is "working", then you aren't running the code above. Perhaps that file already existed with the data in it?

As far as the errors go, look at the reponses to your last post. We gave you suggestions on how to fix those exact errors.