xHarbour Reference Documentation > Preprocessor Reference

#undef

Voids a #define constant or pseudo-function.

Syntax

#undef <Constant>

Arguments

<Constant>

This is the symbolic name of the constant or pseudo-function to undefine. It is case sensitive.

Description

The #undef directive removes a symbolic name from the list of previously defined constants. The symbolic name becomes unavailable and can be redefined.

Info

See also:	#define, #if, #ifdef, #ifndef
Category:	Preprocessor directives

Example

// The example demonstrates a typical pattern for #ifdef, #undef and
// #define directives.

   #ifdef DEBUG_LEVEL
      #undef DEBUG_LEVEL
      #define DEBUG_LEVEL     3
   #endif