summing array values

[Ishvite]

I have an assignment to do a simple array program that lets the user enter in 10 grades and then the program will average them and output the average. I need to have two functions and main and I am having trouble understanding how to pass my array values from one function to another. I keep getting a "segmentation fault"

#include <iostream>
using namespace std;

void getGrades(int grades[])
{
   int numOfGrades = 1;

   for (int i = 1; i <= 10; i++)
   {
      cout << "Grade " << numOfGrades++ << ": ";
      cin >> grades[numOfGrades];
   }
}

void averageGrades(int grades[])
{
   int sumOfGrades;

   for (int i = 1; i <= 10; i++)
      sumOfGrades += grades[i];

   cout << "Average Grade: " << (sumOfGrades / 10) << endl;
}

int main()
{
   int grades[10];
   getGrades(grades);
   averageGrades(grades);

   return 0;
}

[3hM2Nwbp]

/* C++ Indices start at 0 */
/* [ code ] Code Here [ /code ] <- Code Tags Are Great */

#include <iostream>
using namespace std;

void getGrades(int grades[])
{
    for (int i = 0; i < 10; i++)
    {
        cout << "Grade " << (i + 1) << ": ";
        cin >> grades[i];
    }
}

void averageGrades(int grades[])
{
    int sumOfGrades;
    for (int i = 0; i < 10; i++)
    {
        sumOfGrades += grades[i];
    }
    cout << "Average Grade: " << (sumOfGrades / 10) << endl;
}

int main()
{
    int grades[10];
    getGrades(grades);
    averageGrades(grades);
    return 0;
}

The segmentation fault was happening because you were writing past the end of your array.

int grades[10] <===> [x] [x] [x] [x] [x] [x] [x] [x] [x] [x]
[0] [1] [2] [3] [4] [5] [6] [7] [8] [9] [ You were writing out here somewhere. ]

[killingthemonkey]

Also, initialize sumOfGrades to 0.

[Ishvite]

Thanks for the help. Just so I understand what I did wrong, when I initialized int i = 1 in my for loop I skipped the array [0] in grades[10] and when i equaled 10 it was writing outside the array [0] to [9]. So if my array had been int grades[11] it still would have worked when i equaled 10, right?

[ascii]

Yup :) Though not very common in C++ a for each loop is awesome for going through each element of an array and not having to worry about problems like going out of the bounds of an array.