example.c

#include <stdio.h>

/*******************************************************
 *                 SAMPLE COMPILATION AND OUTPUT
 *
 * % gcc -o overflow_example example.c ; ./overflow_example
 * I just overflowed, I am now negative!
 * Current Value is: -32768
 * Last Value is: 32767I have looped back upon myself to 0! 
 *
 *******************************************************/

int main(int argc, char *argv[]) {
  short current = 1, last = 0; // Values which are 2 bytes long and range from -32768 to 32767
                               // (including 0), or "16-bit signed integers". 
  while(current != 0) {
    current = current + 1;
    if(current < last) {
      // Current is less than last, but if we're adding how can that possibly happen?!
      // In a word... "Signed Overflow"
      printf("I just overflowed, I am now negative!\nCurrent Value is: %d\nLast Value is: %d\n", 
             current, 
             last);
    }
    last = current;
  }
  printf("I have looped back upon myself to 0!\n");
  return 0;
}