Why is address zero used for the null pointer in C/C++?

CC++Server Side ProgrammingProgramming

Null pointer is a pointer which points nothing.

Some uses of null pointer are:

b) To initialize a pointer variable when that pointer variable isn’t assigned any valid memory address yet.

b) To pass a null pointer to a function argument when we don’t want to pass any valid memory address.

c) To check for null pointer before accessing any pointer variable. So that, we can perform error handling in pointer related code e.g. dereference pointer variable only if it’s not NULL.

In C++ if we assign 0 in any pointer that means the pointer pointing to the NULL.


Float *p = 0 //initializing the pointer as NULL.


   Declare a pointer p of the integer datatype.
      Initialize *p= NULL.
   Print “The value of pointer is”.
      Print the value of the pointer p.


 Live Demo

#include <stdio.h>
int main() {
   int *p= NULL;//initialize the pointer as null.
   printf("The value of pointer is %u",p);
   return 0;


The value of pointer is 0.
Published on 03-Apr-2019 09:33:25