Infinite loop while attempting to read char by char until end of line

[jdwright]

//Reads in digits for an array.
int getFactors (int ary[], ifstream &inFile)
{
    char k = '0';
    int count;
    
    for (int i = 0; i < MAX; i++)
    {
        while (k != '\n')
        {
            count++;
            inFile >> k;
            ary[i] = k - '0';   //Convert character to integer and store in array.
            cout << ary[i]; //TEST
        }
    }
    return count;
}

I have this function which is intended to read input from a file one character at a time and convert and store the integers in an array. When I run this with the //TEST part that you see below, I get an infinite loop that looks like this:

6946123853213872663123654321222222222222222222222222222222555555555556666666666666666666999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999387687687687687687687687687687658485949392039999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999

This part of the code was given by my instructor:

while (k != '\n')
        {
            ...
            inFile >> k;
            ary[i] = k - '0';
            ...
         }

If anybody can see what is causing it to fail, please help out!

[jdwright]

//TEST part that you see above***

[novellof]

What is MAX??

[jdwright]

MAX is the number of elements in the array...

[JLBorges]

const int MAX = 100 ;

int getFactors( int ary[], std::istream& stm )
{
    char k = '0';
    int count = 0 ; // initialise

    while( stm.get(k) && // a character was read ( note: stm >> k skips whitespace; it won't read a new line)
           k != '\n' && // and it was not a newline
           count < MAX ) // and the array bound is not exceeded
    {
        if( k >= '0' && k <= '9' ) // isdigit : if it is a digit
        {
            ary[count] = k - '0';   // Convert character to integer and store in array.
            ++count ;
        }
        else { /* the character is not a digit. throw it away(?) */ }
    }

    return count;
}

[jdwright]

Thanks @JLBorges, that was helpful and I modified my code using your suggestions. I'm having a weird thing happening now though. As the program steps through the input file, when it encounters a number that takes up the entire array (30 integers) it goes back and gets the number before that one before moving on the next one..?

[JLBorges]

Posting your code would be a good idea.

[jdwright]

Here is my modified function:

int getFactors (int ary[], ifstream &inFile)
{
	char k = '0';
	int count = 0;
    
	while (inFile.get(k) && k != '\n' && count < MAX)
	{
        if (k >= '0' && k <= '9')
        {
            ary[count] = k - '0';
            count++;
        }
	}
    
	return count;
}

And here's what is happening in main:

int main()
{
    int topFactor[MAX], bottomFactor[MAX], product[MAX];
    int t_NUM, b_NUM, p_NUM;
    
    ifstream inFile;
    inFile.open ("/Users/jordanfleming/Desktop/BigNumbersV2.txt");
    
    while (inFile)
    {
        t_NUM = getFactors (topFactor, inFile);
        b_NUM = getFactors (bottomFactor, inFile);

        printUnEArray (topFactor, t_NUM);               //TEST
        cout << endl;                                            //TEST
        printUnEArray (bottomFactor, b_NUM);        //TEST
        cout << endl;                                           //TEST
    }
    
    inFile.close();
    
    return 0;
}

And here is the output that I am getting:

600000000000000000000000000000
900000000000000000000000000000
461230000000000000000000000000
853210000000000000000000000000
387266312300000000000000000000
654321000000000000000000000000
222222222222222222222222222222
654321000000000000000000000000
555555555556666666666666666666
654321000000000000000000000000
999999999999999999999999999999
654321000000000000000000000000
999999999999999999999999999999
654321000000000000000000000000
999999999999999999999999999999
654321000000000000000000000000
399999999999999999999999999999
876876876876876876876876876876
399999999999999999999999999999
584859493920396876876876876876
399999999999999999999999999999
584859493920396876876876876876

Also, the input file is this:
6
9
46123
85321
3872663123
654321
222222222222222222222222222222
555555555556666666666666666666
999999999999999999999999999999
999999999999999999999999999999
999999999999999999999999999999
3
876876876876876876876876876876
58485949392039

[JLBorges]

And what does your printUnEArray() look like?

[jdwright]

A simple print function:

void printUnEArray (int ary[])
{
    for (int i = 0; i < MAX; i++)
    {
        cout << ary[i];
    }
}

Note: The reason I am printing out all the way to MAX instead of the exact number of elements in the array has to do with the purpose of other parts of the program.

[JLBorges]

int getFactors (int ary[], std::ifstream &inFile)
{
	char k = '0';
	int count = 0;
	
	// initialise the array to all zeroes
	for( int i = 0 ; i < MAX ; ++i ) ary[i] = 0 ; // *** added ****

	while (inFile.get(k) && k != '\n' && count < MAX)
	{
        if (k >= '0' && k <= '9')
        {
            ary[count] = k - '0';
            count++;
        }
	}

        // ******************* added ***********************
        if( k != '\n' ) // if there are more characters left in this particular line
                inFile.ignore( 1000000, '\n' ) ; // throw them away
        // http://www.cplusplus.com/reference/istream/istream/ignore/

	return count;
}

[jdwright]

Perfect. Thank you and thanks for the reference. Definitely need to do more research about how all this works.