fstream and overloading questions

[Patriots12]

Hello, I posted earlier about my school project giving me some trouble, and while that was resolved, I've run in to some more, much more daunting issues.

#include<iostream>
#include<conio.h>
#include<stdio.h>		//load libraries
#include<stdlib.h>
#include<time.h>
#include<fstream>
#include<string>
using namespace std;

	
	string inFile;		//declare file names
	string outFile;

	instream.open("inFile.txt");   //open the files
	outstream.open("outFile.txt");

	ifstream instream(inFile.data());	//get the data
	ofstream outstream(outFile.data());     //and declare fstream names


	if (instream.fail())
	{
	cout << "Input file opening failed.\n";  //confirm file opened
	exit(1);
	}

	if (outstream.fail())
	{
	cout << "Output file opening failed.\n"; //confirm file opened
	exit(1);
	}
	instream.close();
	outstream.close();  //close the files



class MathProblem 	//create mathproblem class
{
private:		
	
	int first;
	int second;
	int getOper;		//private variables
	int answer;
	int correct;
	char operate;
	
public:

	void showOther();
	void showProblem();		//public member functions
	void setProblem();
	void getAnswer();
};	

void MathProblem::setProblem()	//start setProblem
{

	srand(time(0));	//changes the rand() each time function is called
	first = rand() % 60 + 12;	//makes a random integer between 12 and 72
	second = rand() % 10 + 1;	//makes a random integer between 1 and 10
	getOper = rand() % 4 + 1;	//makes a random integer between 1 and 4, then selects an operator based on that number and the comparisons below
	
	if (getOper == 1)
	{
		operate = '+';		//if getOper is 1, the equation is addition
	}
	if (getOper == 2)
	{
		operate = '-';		//if getOper is 2, the equation is subtraction
	}
	if (getOper == 3)
	{
		operate = '*';		//if getOper is 3, the equation is multiplication
	}
	if (getOper == 4)
	{
		operate = '/';		//if getOper is 4, the equation is division
	}	

}

void MathProblem::showProblem()
{
	outstream << "For division, don't forget to round up!" << endl;	//reminding user to round up for division, because calculating % is lol
	outstream << first << operate << second << " = " << endl;		//display problem
	
	if (getOper == 1)
	{
	correct = first + second;		//using the getOper comparisons found in setProblem, display appropriate equation
	}
	if (getOper == 2)
	{
	correct = first - second;		//using the getOper comparisons found in setProblem, display appropriate equation
	}
	if (getOper == 3)
	{
	correct = first * second;		//using the getOper comparisons found in setProblem, display appropriate equation
	}
	if (getOper == 4)
	{
	correct = first / second;		//using the getOper comparisons found in setProblem, display appropriate equation
	}
}

void MathProblem::getAnswer()
{
	instream >> answer;		//get answer from the user
}

void MathProblem::showOther()
{

	outstream << "Your answer was: " << answer << endl;		//tell the user what their answer was
	outstream << "The correct answer was: " << correct << endl;		//tell the user the correct answer
	outstream << "Were you correct? ";		//compare the users answer with the correct answer
	if (answer == correct)
	{
		outstream << "1";		//display '1' if the user was right
	}
	else
	{
		outstream << "0";		//display '0' if the user was wrong
	}
}

class MathProblemWithAnswer : public MathProblem		//create MathProblemWithAnswer class, and inherit MathProblem
{
private:

	int right;		//private variable

public:
	void setProblem(int first, int second, char oper8);
	void getAnswer(int input);			//set overloaded functions with their paramaters
	void showOther(int compare);
};

void MathProblemWithAnswer::setProblem(int num1, int num2, char oper8)		//use the same basic function, but different variables that are stated here
{
	srand(time(0));
	num1 = rand() % 60 + 12;
	num2 = rand() % 10 + 1;
	char randOper = rand() % 4 + 1;
	
	if (randOper == 1)
	{
		oper8 = '+';
	}
	if (randOper == 2)
	{
		oper8 = '-';
	}
	if (randOper == 3)
	{
		oper8 = '*';
	}
	if (randOper == 4)
	{
		oper8 = '/';
	}	
}

void MathProblemWithAnswer::getAnswer(int input)	
{
	instream >> input;	//get answer from the user
}

void MathProblemWithAnswer::showOther(int compare)		//compare the input with the correct answer, like before
{

	outstream << "Your answer was: " << right << endl;
	outstream << "The correct answer was: " << compare << endl;		
	outstream << "Were you correct? ";
	if (right == compare)
	{
		outstream << "1";
	}
	else
	{
		outstream << "0";
	}
	
}



void main()
{
	MathProblem problem;
	problem.setProblem();		//call all o' dem functions
	problem.showProblem();
	problem.getAnswer();
	problem.showOther();

	MathProblemWithAnswer problemAnswer;
	void setProblem();
	void getAnswer();			//call dem functions too
	void showOther();	

}

Basically, everything above the class MathProblem declaration is giving me trouble. I've tried putting it all in a function, in the main, as a class, moving it around, nothing will work. all of my 'outstream' instances are saying they have an undeclared identifier, although I did have it working (I believe when it was in my int main())

the bolded If statement says expected a declaration, only one stream.close() is underlined...

basically everythings a mess, and nothing I do seems to get me anywhere, and all the errors seem to be completely irrelevent (like saying 'expected a ;' when there is one before it)

Also, my MathProblemWithAnswer business is supposed to demonstrate I understand inheritance, but my lab instructor explained it miserably, I think it's basically supposed to do the exact same thing as MathProblem, but use overloaded functions, but I don't know how to declare that in the Main(), as adding parameters to the () after the function name always yields errors.

I apologize for such a long post, but it's pretty late and I'm getting desperate for some guidance, any help will go a long way! Thank you.

tl;dr:

fstreams are hard, were barely taught them.

[coder777]

You need to put line 11-33 into a function (and call that function).

Line 17/18 must be placed before 14/15. An object must be instantiated (line 17/18) before it can be accessed (line 14/15).

On line 17/18 the streams will be opened so you can omit line 14/15.

Since the data() function of string does not necessarily has a trailing 0 you need to change line 17/18 to:

	ifstream instream(inFile.c_str());	//get the data
	ofstream outstream(outFile.c_str());     //and declare fstream names 

to notify the user use cout not outstream
to get input from the user use cin not instream
since you don't need outstream/instream you can discard line 11-33 entirely

lines 197-199 are function declarations not calls. Omit void to call them