Is #if defined MACRO equivalent to #ifdef MACRO?

Question

I have code that I want to have two modes, debug and verbose. I define them in my header file as,

#define verbose TRUE
#def         


        

Answer 1

#if defined(MACRO) is the same as #ifdef MACRO, but is longer. On the other hand it allows to add extra conditions with || or &&.

#if MACRO is similar to #ifdef MACRO but not 100%. If MACRO is 0 then #if MACRO will be negative - it requires MACRO to be defined and not be 0. #ifdef checks only whether it is defined even without value (#define MACRO).

Now is modern to use #if and enable/disable definitions with value 1 or 0:

#define FLAG_X 1 // or 0