C Tutorial/Preprocessor/undef


Deprecated: Constant E_STRICT is deprecated in /var/www/cppe.ru/www/includes/exception/MWExceptionHandler.php on line 179

Deprecated: Creation of dynamic property PPDStack::$accum is deprecated in /var/www/cppe.ru/www/includes/parser/Preprocessor_DOM.php on line 803

Deprecated: Constant E_STRICT is deprecated in /var/www/cppe.ru/www/includes/exception/MWExceptionHandler.php on line 179

Deprecated: Constant E_STRICT is deprecated in /var/www/cppe.ru/www/vendor/mediawiki/at-ease/src/Functions.php on line 48
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undef

To undefine the value defined by "#define" and specify a new value.


#include <stdio.h>
#define VAL 40;     
#undef  VAL          
#define VAL 50      
main()
{
    printf ("%d\n", VAL);  
}
50