"terminating" array in C [closed] - arrays

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if my program needs an int array of size of at most 10 and my user is given the option to "terminate" the data set when entering -1, what are some ways i can acheive this?
By "terminating", I am referring to if my user enters -1 while inputting the values in the array, the array stopps scanning user input values immediately and returns the values that were entered previously, discarding -1.
The array size can be at most 10, but i do not know how to process the array when my user enters less than 10 values.
Example:
Enter data -> 1 2 3 4 5 -1
data[10] contains {1, 2, 3, 4, 5}
Enter data -> 1 2 3 4 5 6 7 8 9 10
data[10] contains {1, 2, 3, 4, 5, 6, 7, 8, 9, 10}
Enter data -> 1 2 3 4 5 6 7 -1
data[10] = {1, 2, 3, 4, 5, 6, 7}
I'm not allowed to use break statements. Right now I can only think of searching for -1 and turning it and the reset of the values into 0. This is what i have so far:
int getValues(int arr[])
{
int loop; // used to iterate through for loop
int terminate; // used to iterate through for loop when user terminates data set
loop = 0;
terminate = 0;
printf("Enter 10 integer values -> ");
for (loop = 0; loop < 10; loop++)
{
scanf("%d", &arr[loop]);
if (arr[loop] == -1)
{
arr[loop] = 0;
for (terminate = loop; terminate < 10; terminate++)
{
arr[terminate] = 0;
}
}
}
printf("\n");
return 0;
}

Answer 1

Maybe you want this: We stop the loop as soon as the user has entered -1 but we simply store that -1 in the array and we use that -1 one as terminator.
#include <stdio.h>
int getValues(int arr[])
{
int loop; // used to iterate through for loop
printf("Enter 10 integer values -> ");
for (loop = 0; loop < 10; loop++)
{
scanf("%d", &arr[loop]);
if (arr[loop] == -1)
{
loop = 10 - 1; // simulate a break
}
}
printf("\n");
return 0;
}
int main()
{
int arr[10];
getValues(arr);
// print array values and stop at the -1 terminator
for (int i = 0; i < 10 && arr[i] != -1; i++)
printf("arr[%d] = %d\n", i, arr[i]);
}
Another possibility is to store the size of the array:
#include <stdio.h>
int getValues(int arr[], int *size)
{
int loop; // used to iterate through for loop
printf("Enter 10 integer values -> ");
for (loop = 0; loop < 10; loop++)
{
scanf("%d", &arr[loop]);
if (arr[loop] == -1)
{
*size = loop; // store the size
loop = 10 - 1; // simulate a break
}
}
printf("\n");
return 0;
}
int main()
{
int arr[10];
int size;
getValues(arr, &size);
// now size contains the number of elements of the array
for (int i = 0; i < size; i++)
printf("arr[%d] = %d\n", i, arr[i]);
}
There are still issues with this code:
the return value of scanf is ignored
there is no check for out of bounds array access, In other words, the user can enter more than 10 numbers and thus write beyond the array bounds which will lead to undefined behaviour (google that term).
the hard coded value 10 is all over the place