Thread: how can I write code to test a[100];

I write some codes as follows:

Code:

int main()
{
  int a[2];
  a[0] = 1;
  a[1] = 1;
  
  return 0;
}

If my printing code is as follow:

Code:

printf("%d\n",a[100]); //a[100] not defined

The result is "segmentation fault";

how can I write code to test a[100];
(I means if a[100] is defined, print
if a[100] is not defined, printf("a[100] is not defined.\n")

how can I carry out?