#ifdef vs #if - which is better/safer as a method for enabling/disabling compilation of particular sections of code?

Question

This may be a matter of style, but there\'s a bit of a divide in our dev team and I wondered if anyone else had any ideas on the matter...

Basically, we have some de

Answer 1

#ifdef just checks if a token is defined, given

#define FOO 0

then

#ifdef FOO // is true
#if FOO // is false, because it evaluates to "#if 0"