mikroC - C Compiler for Microchip PIC microcontrollers

mikroC

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Any processed section can contain further conditional clauses, nested to any depth. Each nested #else, #elif, or #endif directive belongs to the closest preceding #if directive.

The net result of the preceding scenario is that only one code section (possibly empty) will be compiled.

Directives #ifdef and #ifndef

You can use the #ifdef and #ifndef directives anywhere #if can be used. The #ifdef and #ifndef conditional directives let you test whether an identifier is currently defined or not. The line

#ifdef identifier

has exactly the same effect as #if 1 if identifier is currently defined, and the same effect as #if 0 if identifier is currently undefined. The other directive, #ifndef, tests true for the “not-defined” condition, producing the opposite results.

The syntax thereafter follows that of the #if, #elif, #else, and #endif.

An identifier defined as NULL is considered to be defined.

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