fork download
copy 
  1. #include <stdio.h>
  2.  
  3. #define SENTINEL -1
  4.  
  5. void foo(int *a) {
  6. 	size_t n = 0; 
  7. 	while (*a != SENTINEL) {
  8. 		a++;
  9. 		n++;
  10. 	}
  11. 	printf("%zu elements.\n", n);
  12. }
  13.  
  14. int main(void) {
  15. 	foo((int[]){4, 5, 6, 7, 8, SENTINEL});
  16. 	foo((int[]){-1, -2, SENTINEL});
  17. 	foo((int[]){1, 2, 3}); // no sentinel -- UB!!
  18. }
  19.  
Success #stdin #stdout 0.01s 5512KB
comments (?)
stdin
copy 
Standard input is empty
stdout
copy 
5 elements.
0 elements.
8 elements.
https://ideone.com/YWrkfI
sentinel array
language:
C (gcc 8.3)
created:
2 years ago
visibility:
secret

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!