Is something wrong with my return value?

Question

I had to make a function that prints out all the numbers in an array (provided in 'main'), within a certain index (eg between 0-11, or 2-6, etc). Then the function has to return the value of the last index value.

For example, given the array

{8, 3, 6, 7, 9, 5, 3, 8, 6, 7, 4, 5}

If I input the numbers 2 and 7 , then it should printf {6 7 9 5 3 8} , and then return 8. However it keeps returning 6`.

int index(int data[], int low, int high)
{       
    while(low <= high) {
        printf("%d\n", data[low]);
        low++;
    }

    return data[low];     
}

/* I know I could just put return[high], but i though it  
   wouldn't matter since 'low' keeps incrementing until low == high */

int main()
{       
    int activities[12] = {8, 3, 6, 7, 9, 5, 3, 8, 6, 7, 4, 5}; 
    int low, high;
    int x;

    printf("What is the starting day?  ");
    scanf("%d", &low);
    printf("What is the ending day?  ");
    scanf("%d", &high);

    x = index(activities, low, high);
    printf("\n\nThe function returns this value: %d",x);

    return 0;
}

Answer 1

When you return data[low] , low is already incremented by 1. The last value of low would be high + 1 . The while condition would fail and then come out of the loop.

So, your code should be:

return data[high];

Answer 2

If you want to return the last value using the low variable you can simply do

return data[--low];

Because while checking the condition it fails when the value of low is greater than the value of high .

For example the if you enter low = 2 and high = 7, in the last iteration low become 8 and break the loop which now points to value 6 in activities array since activities[8] == 6

So I would suggest to simply return the value using the last index that is,

 return data[high];

Answer 3

Just return data[high]; You incremented low to one after high so it returns that value.