Simple C++ Summing Program

Question

This is my first time using C++ and I am writing a small program to sum up to ten numbers (doubles) that will be entered in the command prompt.

I have written the following code and I cannot figure out why it will not produce the desired result.

int main()
{
    double num[10];
    double sum = 0;
    int i;
    int n = 10;

    while (scanf_s("%lf", &num) != EOF)
    {
        for (i = 0; i < n; ++i)
        {
            scanf_s("%lf", &num);
            sum = sum + num[i];
        }
    }

    cout << sum;

    system("pause");
    return 0;
}

The data entry is terminated with a control D. In my eyes it should run fine but it doesn't. Could someone please give me some pointers for solving this, I don't just want to be told the correct way I would rather learn it myself.

Answer 1

The problem is that &num is the address of the array. SO you read your value always in num[0] meaning that num[i] is random in most of the cases.

Try to change your loop:

for (i = 0; i < n && (cin>>num[i]); ++i)
{
    sum = sum + num[i];
}