A pointer that is not assigned any value but NULL is known as NULL pointers.
If we don't have any address to be specified in the pointer at the time of declaration,we can assign a NULL value.
int *p = NULL;
Operations with Pointers:
Possible-
Pointer increment
Pointer decrement
Constant addition
Constant subtraction
Subtraction of two pointers
Not Possible-
Addition of two pointers
Multiplication of two pointers
Multiplying the pointers with the constant values.