text: #include <stdio.h>
  int main(void)
  {
      int urn[5] ={ 100, 200, 300, 400, 500 };
      int* ptr1, * ptr2, * ptr3;
  
      ptr1 = urn;
      ptr2 = &urn[2];
  
      printf("pointer value, deferenced pointer, pointer address:\n");
      printf("ptr1 = %p, *ptr1 = %d, &ptr1 = %p\n", ptr1, *ptr1, &ptr1);
  
      ptr3 = ptr1 + 4;
      printf("\nadding an int to a pointer:\n");
      printf("ptr1 + 4 = %p, *(ptr1 + 4) = %d\n", ptr1 + 4, *(ptr1 + 4));
  
      ptr1++;
      printf("\nvalues after ptr++:\n");
      printf("ptr1 = %p, *ptr1 = %d, &ptr1 = %p\n", ptr1, *ptr1, &ptr1);
  
      ptr2--;
      printf("\nvalues after --ptr2:\n");
      printf("ptr2 = %p, *ptr2 = %d, &ptr2 = %p\n", ptr2, *ptr2, &ptr2);
  
      --ptr1;
      ++ptr2;
  
      printf("\nPointers reset to original values:\n");
      printf("ptr1 = %p, ptr2 = %p\n", ptr1, ptr2);
  
      printf("\nsubtracting one ponter from another:\n");
      printf("ptr2 = %p, ptr1 = %p, ptr2 - ptr1 = %td\n", ptr2, ptr1, ptr2 - ptr1);
      
      printf("\nsubtracting an int from a pointer:\n");
      printf("ptr3 = %p, ptr3 - 2 = %p\n", ptr3, ptr3 - 2);
  
      return 0;
  }