Question

4 Which one of the following represents a correct and safe declaration of NULL ?
a) typedef((void *)0) NULL;
b) typedef NULL(char *)0;
c) #define NULL((void *)0)
d) #define NULL((char*)0)

Answer 1

Answer:

c) #defineNULL(Char*)0)

, Hope it helps

Answer 2

From the given options the one which represents a correct and safe declaration of NULL is t#define NULL((char*)0) (Option d)

• The C library Macro NULL is actually the value of any null pointer constant, which can be defined as ((void*)0), 0, or 0L. That completely depends upon the compiler itself. Like - #define NULL ((char *)0) or, #define NULL 0L, or #define NULL 0.
• NULL should be used as a pointer.
• To avoid errors the NULL won't be used as constant 0, we define #define NULL((char *)0).
• 
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