Pointer to pointer in c

Example

int a = 10;
int *ptr = &a;

Where, ptr is a pointer which is holding the address of variable a.

If we need to hold the address of ptr, what will be the solution?

Pointer to Pointer.

Declaration of pointer to pointer (double pointer)

int a = 10;
int *ptr = &a;
int **dptr = &ptr;

Visual Representation of the above code

Referencing and dereferencing a double pointer

i)Referencing

Assigning an address to the pointer.

ii)Dereferencing

Accessing the value stored at the pointer.

Example

/*
 * Program  : Pointer to Pointer
 * Language : C
 */

#include<stdio.h>

int main()
{
    int a = 10;
    int *ptr = &a;     //ptr references a
    int **dptr = &ptr; //dptr references ptr

    printf("Address of a = %p\n",&a);
    printf("ptr is pointing to the address = %p\n",ptr);
    printf("dptr is pointing to the address = %p\n",dptr);
    printf("Value of a = %d\n",a);
    printf("*ptr = %d\n",*ptr);
    printf("**dptr = %d\n",**dptr);

    return 0;
}

*ptr -> *1024 -> value stored at the memory 1024 is 10 ->10

**dptr -> *(*2024)-> value stored at the memory address 2024 is 1024 -> *1024->value stored at the memory address 1024 is 10 -> 10

Find the output

Using the above diagram, can you find the output of the program?

Don't click me straight away.