A null pointer is a pointer which points nothing.
Some uses of the null pointer are:
- To initialize a pointer variable when that pointer variable isn’t assigned any valid memory address yet.
- To pass a null pointer to a function argument when we don’t want to pass any valid memory address.
- To check for a 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.
Algorithm
Begin. Declare a pointer p of the integer datatype. Initialize *p= NULL. Print “The value of pointer is”. Print the value of the pointer p. End.
Example
#include <stdio.h>
int main() {
int *p= NULL;//initialize the pointer as null.
printf("The value of pointer is %u",p);
return 0;
}
Output
The value of pointer is 0.