Accepting any number of inputs from scanf function

Question

I am trying to read an unknown number of inputs using scanf function.

int a[100];
int i = 0;

while((scanf("%d", &a[i])) != '\n')
 i++;

// Next part of the code

But this function is not going to next part of the code, seems like there is an infinite while loop.

How Do I solve this logical error? Is there any other alternatives to scanf like sscanf to read integers into an array?

Answer 1

scanf returns the number of input items that have been successfully matched and assigned, thus it is reasonable to do:

while(scanf(...) == 1)

Now you want to be able to read multiple numbers, each defined on the new line. Then you could simply do this:

int array[100];
int i = 0;

while(i < 100 && scanf("%d\n", &array[i]) == 1)
    i++;

note that this reading will stop only if invalid input is entered (for example letter q) or when you input the end-of-input control code, which is Ctrl+Z (on Windows) or Ctrl+D (on Mac, Linux, Unix).

Answer 2

The return value of scanf is the number of input items successfully matched and assigned, so try this to end when a non-numeric input is encountered:

while (i < 100 && (scanf("%d", &a[i])) == 1) { i++; }