Menu
I always think simply if(p != NULL){..} will do the job. But after reading this Stack Overflow question, it seems not.
So what's the canonical way to check for NULL pointers after absorbing all discussion in that question which says NULL pointers can have non-zero value?
819
So that if p is a null pointer then it must compare equal to any null pointer including NULL , in which case p != NULL would evaluate to false. Conversely, if p points to an object or function then it must compare unequal to any null pointer in which case p != NULL would evaluate to true.
Hence when a pointer to a null pointer is created, it points to an actual memory space, which in turn points to null. Hence Pointer to a null pointer is not only valid but important concept.
The preprocessor macro NULL is defined as an implementation-defined null pointer constant, which in C99 can be portably expressed as ((void *)0) which means that the integer value 0 converted to the type void* (pointer to void).
I always think simply if(p != NULL){..} will do the job.
It will.
170
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With
