Any reason to use hex notation for null pointers?

Question

I'm currently improving the part of our COM component that logs all external calls into a file. For pointers we write something like (IInterface*)0x12345678 with the value being equal to the actual address.

Currently no difference is made for null pointers - they are displayed as 0x0 which IMO is suboptimal and inelegant. Changing this behaviour is not a problem at all. But first I'd like to know - is there any real advantage in representing null pointers in hex?

Answer 1

In C or C++, you should be able to use the standard %p formatting code, which will then make your pointers look like everybody else's.

I'm not sure how null pointers are formatted in Win32 by %p, on Linux I think you get "null" or something similar.

Answer 2

Using the notation 0x0 (IMO) makes it clearer that it's referring to an address (even if it's not the internal representation of the null pointer). (In actual code, I prefer would using the NULL macro, though, but it sounds like you're talking specifically about debugging spew.)

It gives some context, just like I prefer using '\0' for the NUL-terminator.

It's a stylistic preference, though, so do what appeals to you (and to your colleagues).