

#elif                Preprocessing Directive                #elif




Include code conditionally


The  preprocessing directive  #elif  conditionally includes  code
within a  program.  It can be used after  any of the instructions
#if, #ifdef, or #ifndef.

If the  conditional expression of  the preceding #if,  #ifdef, or
#ifndef directive is false  (i.e., evalutates to zero) and if the
current condition is true  (i.e., evaluates to a value other than
zero), then group is included  within the program, up to the next
#elif, #else,  or #endif directive.   An #if, #ifdef,  or #ifndef
directive may be followed by any number of #elif directives.

The constant-expression  must be  an integral expression,  and it
cannot include a sizeof  operator, a cast, or an enumeration con-
stant.  All macro  substitutions are performed upon the constant-
expression  before it  is evaluated.   All integer  constants are
treated as  long objects, and  are then evaluated.   If constant-
expression includes character constants, all escape sequences are
converted into characters before evaluation.

***** See Also *****

#else, #endif, #if, #ifdef, #ifndef, C preprocessor































COHERENT Lexicon                                           Page 1


