Quiz

[paulthepenguin]

So, I'm trying to make a quiz about myself for my friends, and to further my knowledge of C++. My only problem is, I need help writing their answers to a text file so they can email me their results. I currently have:

void q1(int &correct)
{
    ofstream info;
	char input;

    gateway1:
    system("cls");
    
	cout << "What is my favorite color? \n";
	cout << "\nA. Yellow";
	cout << "\nB. Orange";
	cout << "\nC. Purple";
	cout << "\nD. Green \n";
	cout << "\nInput: ";
	cin >> input;


    if (input == 'c')
    {
       correct++;
    }
    else if (input == 'a' || input == 'b' || input == 'd')
    {
         correct+= 0;
    }
    else
    {
        cout << "Invalid Input. Try again.";
        system("pause>nul");
        goto gateway1;
    }
    info.open("Results.txt");
    info << "Question 1: c:" << input;
}


void q2(int &correct)
{
    ofstream info;
	char input;

    gateway1:
    system("cls");
    
	cout << "What is my favorite movie? \n";
	cout << "\nA. Mulan";
	cout << "\nB. Winnie The Pooh";
	cout << "\nC. The Goofy Movie";
	cout << "\nD. Tangled \n";
	cout << "\nInput: ";
	cin >> input;


    if (input == 'd')
       correct++;
    else if (input == 'a' || input == 'b' || input == 'c')
         correct += 0;
    else
    {
        cout << "Invalid Input. Try again.";
        system("pause>nul");
        goto gateway1;
    }
    info.open("Results.txt");
    info << "\nQuestion 2: d:" << input << endl;
}

But all it writes in the text file is:

Question 2: d:<input>

<input> of course, being replaced with whatever letter they put in.
Help?

[Need4Sleep]

The file is fine as a small program, but you're using some very unhealthy programming practices at the moment. Goto is messy and should be avoided 99% of the time, i cant even think of an example off my head where a goto is the only option. It makes reading code and the program a whole lot more complicated. Goto's can commonly be replaced with while loops or functions(which also make code a whole of easier to read!). Another bad habit is using the system("cls") function. Here is a list of what the system needs to do before calling the CLS function:

suspend your program

call the operating system

open an operating system shell (relaunches the O/S in a sub-process)

the O/S must now find the CLS command

allocate the memory to execute the command

execute the command

deallocate the memory

exit the OS

resume your program

As you can see, the function can be very memory heavy and slow. Instead use this function(implying that you use windows):

void cls() //windows h function to replace screen with nulls
{
  DWORD n;
  DWORD size;
  COORD coord = {0};
  CONSOLE_SCREEN_BUFFER_INFO csbi;
  HANDLE h = GetStdHandle ( STD_OUTPUT_HANDLE );
  GetConsoleScreenBufferInfo ( h, &csbi );
  size = csbi.dwSize.X * csbi.dwSize.Y;
  FillConsoleOutputCharacter ( h, TEXT ( ' ' ), size, coord, &n );
  GetConsoleScreenBufferInfo ( h, &csbi );
  FillConsoleOutputAttribute ( h, csbi.wAttributes, size, coord, &n );
  SetConsoleCursorPosition ( h, coord );
}

This function simply reads all characters on the screen and replaces them with whitespaces. It takes a whole lot less memory and is simple to call.
---------------------------------------------------------------------------------------------------------------

Onto the actual program: As a note, make sure you are closing your files after opening them. Using your constructor to open files can be a lot more convenient also, as in:

ofstream info("Results.txt");
//...
info.close();

Your functions could also use some trimming, if you have say, 25 questions, thats 25 different ofstream objects you're creating. I used a reference to an ofstream object to save memory and only have to open the file once. Heres my revised code(works on my computer fine).

#include <iostream>
#include <fstream>
#include <windows.h>
using namespace std;

void q1(int &correct, ofstream& info)
{
	char input;

    gateway1:
    system("cls");

	cout << "What is my favorite color? \n";
	cout << "\nA. Yellow";
	cout << "\nB. Orange";
	cout << "\nC. Purple";
	cout << "\nD. Green \n";
	cout << "\nInput: ";
	cin >> input;


    if (input == 'c')
    {
       correct++;
    }
    else if (input == 'a' || input == 'b' || input == 'd')
    {
         correct+= 0;
    }
    else
    {
        cout << "Invalid Input. Try again.";
        system("pause>nul");
        goto gateway1;
    }
    info << "Question 1: c:" << input;
}


void q2(int &correct, ofstream& info)
{
	char input;

    gateway1:
    system("cls");

	cout << "What is my favorite movie? \n";
	cout << "\nA. Mulan";
	cout << "\nB. Winnie The Pooh";
	cout << "\nC. The Goofy Movie";
	cout << "\nD. Tangled \n";
	cout << "\nInput: ";
	cin >> input;


    if (input == 'd')
       correct++;
    else if (input == 'a' || input == 'b' || input == 'c')
         correct += 0;
    else
    {
        cout << "Invalid Input. Try again.";
        system("pause>nul");
        goto gateway1;
    }
    info << "\nQuestion 2: d:" << input << endl;
}

int main()
{
    int correct;
    ofstream info("Results.txt");
    q1(correct, info);
    q2(correct, info);
    info.close();
    return 0;
}

[paulthepenguin]

I've heard that goto is a horrible option to use, buy with my limited knowledge of C++, I wasn't sure what other option I had. This has helped me greatly, thank you.