Precompiler ifndef
Revision as of 05:55, 30 December 2007 by Sandman (talk | contribs) (New page: category:precompiler == Definition == '''#ifndef''' <what to check> :<if block> ['''#else :<else block>] '''#endif''' Checks if ''what to check'' was previously defined in the code. ...)
Definition
#ifndef <what to check>
- <if block>
[#else
- <else block>]
#endif
Checks if what to check was previously defined in the code. If it isn't, the code in if block will be compiled. If it is, the code in else block will be compiled or when there is no else block, the compiler will continue after #endif.
It is the opposite of #ifdef.
| Precompiler statements | |
| #define • #ifdef • #ifndef • #endif • #else • #if | |