What does the symbol \0 mean in a string-literal?

Question

Consider following code:

char str[] = \"Hello\\0\";

What is the length of str array, and with how much 0s it is ending?

Answer 1

What is the length of str array, and with how much 0s it is ending?

Let's find out:

int main() {
  char str[] = "Hello\0";
  int length = sizeof str / sizeof str[0];
  // "sizeof array" is the bytes for the whole array (must use a real array, not
  // a pointer), divide by "sizeof array[0]" (sometimes sizeof *array is used)
  // to get the number of items in the array
  printf("array length: %d\n", length);
  printf("last 3 bytes: %02x %02x %02x\n",
         str[length - 3], str[length - 2], str[length - 1]);
  return 0;
}