Thread: Help! I cannot figure out what I'm doing wrong here!

For this, it is supposed to read in the answers entered by the user and compare it to the array containing the correct answers. It reads them in, but I can't get it to compare in the QuestonsCorrect function. Any help is greatly appreciated!

Code:

#include <iostream>                 // include standard I/O library
#include <string>                   // include C++ string class handling
#include <iomanip>					// include input/output function
#include <cmath>					// include C++ math function
#include <cstdlib>					// include standard utilities
using namespace std;

/* ========================================================================== */
/* GLOBAL CONSTANTS */
const int NUMBER_OF_ANSWERS = 20;
const int CORRECT_TO_PASS = 15;
int numCorrect = 0;
int numIncorrect = 0;


/* ========================================================================== */
/* FUNCTION PROTOTYPES */
void PrintIntro();
int AskForScores();
void QuestionsCorrect();
void PassExam ();
void QuestionList();
void PrintClosing();
/* ========================================================================== */

typedef char Answers [NUMBER_OF_ANSWERS];

int main ()							//begin main function
{
	int correctAnswer [NUMBER_OF_ANSWERS];
	//Answers correct[] = {"BDAACABACDBCDCCBDA"};
	char correct[] = {"BDAACABACDBCDCCBDA"};

	PrintIntro();
	AskForScores();
	PassExam();
	QuestionList();
	PrintClosing();

}


void PrintIntro()
{
/* print an overall output title for program; print overall title for output
   set width of each line*/
	cout << setw (47) << "====================================="  <<  endl;
	cout << setw (40) << "DMV Driver's License Exam" << endl;
	cout << setw (47) << "====================================="  <<  endl 
		<< endl;
	
}

int AskForScores()
{
int i;
char answerChoices[NUMBER_OF_ANSWERS];

for (i=0; i<NUMBER_OF_ANSWERS; i++)
{
		cout << "Please enter answer " << i+1 << " in CAPITAL LETTERS." << endl;
		cin >> answerChoices[i];

		while (answerChoices[i] < 'A' || answerChoices[i] > 'D') 
		{
			cout << "Invalid input. Please re-enter answer" << i+1 << " in CAPITAL LETTERS." << endl;
			cin >> answerChoices[i];
		}
	

}
cout << answerChoices << endl;
return 0;
}
int QuestionsCorrect (char answerChoices[], char i, char correct[])
{
	
for(int i=0; i < NUMBER_OF_ANSWERS; i++)
{ 
            if ( (answerChoices,correct,i) == false )
			{ 
                 cout << "Answer " << i + 1 << " is incorrect."; 
            }  
    } 
    return 0; 
}

void PassExam()
{

	cout << " You answered " << numCorrect << " questions correctly and " 
		<< numIncorrect << " questions incorrectly." << endl << endl;


	if (numCorrect >= CORRECT_TO_PASS)
		{
			cout << "Congratulations! You passed the driving exam!" << endl << endl;
		}
	else 
	
			cout << "We're sorry, but you have not passed the driving exam." << endl << endl;


}

void QuestionList()
{

	cout << "Please review the questions below so that you are able to pass the exam next time." << endl << endl;

}

void PrintClosing()
{
	cout << "This is the end of the DMV Driving Exam. Goodbye!!" << endl;
}

This doesn't do what you might expect

Code:

            if ( (answerChoices,correct,i) == false )

(answerChoices,correct,i) is a list of expressions that evaluates to the rightmost expression.
That means that you compare the loop counter i to false.
Kurt

Here's a simple C example, should work just fine but not really tested.

Code:

#include <stdio.h>

/* You had this set to 20 but I believe 
 * you only had 18 answers actually set
 */
#define NUM_ANSWERS 18
#define MIN_CORRECT 15

void print_title()
{
	printf("    =====================================\n");
	printf("          DMV Driver's License Exam      \n");
	printf("    =====================================\n");
}

int tally(char * key, char * answers)
{
	int correct = 0;
	int i;
	for(i = 0; i < NUM_ANSWERS; i++)
		if(key[i] == answers[i])
			correct++;

	return correct;
}

int main(void)
{
	int i = 0;
	int e = 0;
	int correct;
	char buf[4];
	char ans[NUM_ANSWERS];
	char key[] = "BDAACABACDBCDCCBDA";
	char * p;

	print_title();
	
	while(i++ < NUM_ANSWERS)	
	{
		if(e == 0)
			printf("Please enter answer %d in CAPITAL LETTERS.\n>", i);
		p = fgets(buf, 3, stdin);
		
		if(p[1] != '\n')
		{
			printf("Invalid input - too many characters. Please re-enter answer %d in CAPITAL LETTERS.\n>", i);
			e = 1;
			i--;
			while(p[0] != '\n') /* I'm on linux... not a portable check */
				p[0] = getchar();
			
			continue;

		} else if(*p < 'A' || *p > 'D') {
			printf("Invalid input. Please re-enter answer %d in CAPITAL LETTERS.\n>", i);
			e = 1;
			i--;
			continue;
		}	
		e = 0;
		ans[i-1] = *p;
	}
	correct = tally(key, ans);

	if(correct >= MIN_CORRECT)
		printf("\nCongratulations! You passed the driving exam!\n");
	else
		printf("\nWe're sorry, but you have not passed the driving exam.\n");

	printf("You answered %d questions correctly and %d incorrectly.\n", correct, NUM_ANSWERS-correct);
	printf("\nThis is the end of the DMV Driving Exam. Goodbye!!\n");

	return 0;
}