#else’ directive can be added to a conditional to provide alternative text to be used if the condition fails. This is what it looks like:
#if expression text-if-true #else /* Not expression */ text-if-false #endif /* Not expression */
If expression is nonzero, the text-if-true is included and the text-if-false is skipped. If expression is zero, the opposite happens.
You can use ‘
#else’ with ‘
#ifdef’ and ‘
© Free Software Foundation
Licensed under the GNU Free Documentation License, Version 1.3.