C Double Pointer (Pointer to Pointer)

// C program to demonstrate pointer to pointer

int main()

{

    int var = 789;

    // pointer for var

    int *ptr2;

    // double pointer for ptr2

    int **ptr1;

    // storing address of var in ptr2

    ptr2 = &var;

    // Storing address of ptr2 in ptr1

    ptr1 = &ptr2;

    // Displaying value of var using

    // both single and double pointers

    printf("Value of var = %d ", var );

    printf("Value of var using single pointer = %d ", *ptr2 );

    printf("Value of var using double pointer = %d ", **ptr1);

  return 0;

}