Conditional Compilation In C: #ifndef #else #endif

https://technotip.com/8602/conditional-compilation-in-c-ifndef-else-endif/

In this video tutorial lets learn about preprocessor command or directives like #ifndef, #else and #endif. These directives are used for conditional compilation. #ifndef works completely opposite to #ifdef

How Does #ifndef Work? The block of code between #ifndef and #endif works only if the macro name is NOT defined. If the macro name is defined, the compiler will skip the entire block of code inside #ifndef from compiling.

C Programming Interview / Viva Q&A List https://technotip.com/6378/c-programming-interview-viva-qa-list/

C Programming: Beginner To Advance To Expert https://technotip.com/6086/c-programming-beginner-to-advance-to-expert/ ... https://www.youtube.com/watch?v=Y7UEY7Cxz7Y