try yourself |run program

#include <stdio.h>
#include <conio.h>

void main(){
  int *ptr1 ;
  int **ptr2 ;
  int v = 100 ;
 clrscr();
 ptr1 = &v ;
 ptr2 = &ptr1 ;
 printf("\n value of *ptr1 = %d",*ptr1);
 printf("\n value of **ptr2 = %d",**ptr2);
 printf("\n value of v = %d",v);
 getch();
}

Program Output

value of *ptr1 = 100
value of **ptr2 = 100
value of v = 100