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Help with my output

bhenlee (7)
I need this program to out put the correct number of answers each person had. I'm unsure where I'm going wrong. Any help would be great!
My output is:
*********************************************************
The purpose of this program is to grade an Exam.
*********************************************************
Enter input file name: data5.1
Thomas abcdeabcdeabcdeabcdeabcde 0
John abcdecabcdecabcdecababcde 0
Steven aaaaaaaaaaaaaaaaaaaaaaaaa 1
Alice abcdecabcdecabcdecaaabcde 1
Justin abcdedabcdedabcded Too few answers
Jennifer abcdedabcdedabcdedabbbabcde Too many answers
Chris abcdefabcdefabcdxxababcde 0
There are 7 student records



Here is my source code. 


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#include <iostream>
#include <iomanip>
#include <fstream>
#include <string>
#include <math.h>
using namespace std;


int GradeMCExam (string, string);
void PrintPurpose ();
void PrintGrade(string name, int score);
bool InvalidAnswers (string answers);


int main ()
{
 // variable declarations
string key;
string student;
string answers;
int score;
//float keylength;
int anslength;
int count;
count = 0;
int numberStudents = 0;
int studentAnsL = answers.length ();
int numRight = 0;
	
void PrintPurpose ();
{
cout << " ********************************************************* " << endl;
cout << "    The purpose of this program is to grade an Exam.  " << endl;
cout << " *********************************************************   " << endl;
}
	
ifstream inFile;
string fileName;
	cout << "Enter input file name:   ";
	cin >>fileName; 
inFile.open( fileName.c_str());
	if (!inFile)
	{
		cout << "Error: Open file failed for " << fileName << endl;
		return 0;
	}

inFile >> key;
int numStudentRight;
int numberRight;	
int keylength = key.length();	
inFile >> student;
inFile >> answers;
	
	while (inFile)
{
	count++;
//	inFile >> student >> answers;
//	score = GradeMCExam (student, answers);
	cout << left << setw(16) << student << "  " << left << setw(30) << answers;
	int studentAnsL = answers.length ();
	if ( keylength < studentAnsL)
	{
		cout << "Too many answers" << endl;
	}
	else if ( keylength > studentAnsL)
	{
		cout << "Too few answers" << endl;
	}
	else 
	{
		numStudentRight = GradeMCExam (student, answers);
		cout << numStudentRight << endl; 
	}
inFile >> student >> answers;	
	
}

cout << "There are" << " " << count << " "<< "student records" << endl;

inFile.close ( );
return 0;
}



int GradeMCExam (string key, string answers)
{
int keylength = key.length();
int score = 0;
int count = 0;
int studentAnsL = answers.length ();
int numStudentRight = 0;
keylength = key.length();
	
	for (int x = 0; x < studentAnsL; x++)
		if ( answers [x] == key [x] )
		{
			numStudentRight++;
		}
		
	if ( InvalidAnswers (answers))
		cout << "Invalid Answers" << endl;
			return numStudentRight;
}

bool InvalidAnswers (string answers)
{
int countAnswer = answers.length ();
bool invalid = true;

	for (int i = 0; i < countAnswer; i++)
		{
			if ( answers [i] = 'a')
					invalid = false;
			else if ( answers [i] = 'b')
					invalid = false;
			else if ( answers [i] = 'c')
					invalid = false;
			else if ( answers [i] = 'd')
					invalid = false;	
			else if( answers [i] = 'e')
					invalid = false;
			else invalid = true;
		}
		return invalid;
	}
Last edited on
Disch (13742)
What makes you think you are going wrong?

EDIT: though one mistake that I do see is that you are using = (assignment) in your if statements, when you probably meant to use == (comparison).
Last edited on
bhenlee (7)
My output should be the number correct at the end of the statement. I don't know why it's not. I'm stumped. My output is supposed to look like this:


*********************************************************
The purpose of this program is to grade an Exam.
*********************************************************
Enter input file name: data5.1
Thomas abcdeabcdeabcdeabcdeabcde 25
John abcdecabcdecabcdecababcde 11
Steven aaaaaaaaaaaaaaaaaaaaaaaaa 5
Alice abcdecabcdecabcdecaaabcde 11
Justin abcdedabcdedabcded Too few answers
Jennifer abcdedabcdedabcdedabbbabcde Too many answers
Chris abcdefabcdefabcdxxababcde Invalid answers 10
There are 7 student records
Last edited on
Disch (13742)
My output should be the number correct at the end of the statement. I don't know why it's not.


It's not? Looks like it is to me.

Your output
Chris abcdefabcdefabcdxxababcde 0


That '0' at the end isn't the number correct?
bhenlee (7)
No.

Its supposed to be the number of correct answers they had. Its compared to the key.
cire (8284)
Shouldn't line 73 be:

numStudentRight = GradeMCExam (student key, answers);
bhenlee (7)
I changed that to try it but it output Invalid Answers at the end of each line. Instead of the score.
cire (8284)
That brings to light another problem.

= is assignment. == is comparison.

You are using assignment in the if/else conditions in InvalidAnswers, which means the only way that function can return true in its current incarnation is if it is fed an empty string.
bhenlee (7)
Correct. I just don't know why I'm not getting my correct number to output. It's supposed to be the number right that matched the key.
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