Syntax of Null Pointer Declaration in C
type pointer_name = NULL; type pointer_name = 0;
We just have to assign the NULL value. Strictly speaking, NULL expands to an implementation-defined null pointer constant which is defined in many header files such as “stdio.h”, “stddef.h”, “stdlib.h” etc.
NULL Pointer in C
The Null Pointer is the pointer that does not point to any location but NULL. According to C11 standard:
“An integer constant expression with the value 0, or such an expression cast to type void *, is called a null pointer constant. If a null pointer constant is converted to a pointer type, the resulting pointer, called a null pointer, is guaranteed to compare unequal to a pointer to any object or function.”