Need help with adding numbers in an array.

[lilmoe1967]

I need to compute the sum of the values in an array of integers of length 25 read from a file named "numbers.txt." Below is my program that lists the numbers and crashes. Please help to solve the issue and please explain the solution.


#include <stdio.h>

int main ()
{

FILE *ifp =fopen ("numbers.txt","r");

int numcases = 25 , i = 0,j,k, num, sum = 0;

int array [numcases];

fscanf(ifp,"%d", &num);

array [i] = num;

printf ("%d", num);

sum = sum + num;

while (array[i] != 0)

{
i++;
fscanf(ifp,"%d", &num);
array [i] = num;
if(num!=0){
printf ("%d \n", num);
}

sum = sum + num;
}
printf("\n = %d", sum);

system("pause");

return 0;
}

[kbw]

You need a similar loop to read in the values. I've put your code in a loop.

	int numcases = 25 , i = 0,j,k, num, sum = 0;

	int array [numcases] = { 0 }; // initialise values to zero

	for (int i = 0; i != 5; ++i) // ask for 5 values
	{
		fscanf(ifp,"%d", &num);
		array [i] = num;

		printf ("%d", num);

		sum = sum + num;
	}

[lilmoe1967]

im sorry, i tried to run your code but it failed to compile saying: variable-sized object may not be initialized, [Warning] excess elements in array initializer, and [Warning] (near initialization for `array')

[kbw]

You're using an old compiler.

The code was meant to demonstrate where you should put a loop in. Apart from the initialisation of the array (using a C++11 construct) and the loop, the rest is your code.

Also, I deliberately initialised only 5 elements even though the array has 25 elements. I expected you to think about it rather than providing a solution you could just copy and hand in.

[lilmoe1967]

Ok so basically you are saying that I should use a for loop instead of a while? Also, I am sorry I misunderstood your intentions. I hope you believe me when I say this is not homework but review for a test I have tomorrow. I need to figure out how to use arrays by tomorrow. Thank you for helping!

[kbw]

Ok so basically you are saying that I should use a for loop instead of a while?

No. I said what I meant. "You need a similar loop to read in the values"

I wasn't commenting on the kind of loop, but the fact that you had to put that code that reads in a value into a loop. Did you not find it strange that you had an array, but you couldn't decide what index to use for the array?

fscanf(ifp,"%d", &num);

array [i] = num;

If I have the time, I'll help as far as I can. To be honest, I thought I did.