pointer to pointer example in c

#include <stdio.h>
int main() 
{
    int i;
    int *ptrToi;           /* Pointer to integer */
    int **ptrToPtrToi;     /* Pointer to pointer */

    ptrToPtrToi = &ptrToi; /* The pointer holds the address of another pointer */
    ptrToi = &i;           /* The pointer holds an integer address */

    i = 10;                /* Direct assignment */
    *ptrToi = 20;          /* Indirect assignment */
    **ptrToPtrToi = 30;    /* indirect assignments twice */

    return 0;
}