Define empathetic. How can I define a define in C? Ask Question Asked 15 years ago Modified 11 months ago In other words, when the compiler starts building your code, no #define statements or anything like that is left. A good way to understand what the preprocessor does to your code is to get hold of the preprocessed output and look at it. Furthermore, a #define 'd constant may be used in the preprocessor: you can use it with #ifdef to do conditional compilation based on its value, or use the stringizing operator # to get a string with its value. How can I use #if inside #define in the C preprocessor? Ask Question Asked 15 years, 10 months ago Modified 11 months ago May 14, 2011 · What is the point of #define in C++? I've only seen examples where it's used in place of a "magic number" but I don't see the point in just giving that value to a variable instead. As far as I know, what you're trying to do (use if statement and then return a value from a macro) isn't possible in ISO C but it is somewhat possible with statement expressions (GNU extension). Oct 28, 2009 · Is it better to use static const variables than #define preprocessor? Or does it maybe depend on the context? What are advantages/disadvantages for each method?. I've found that this works on gcc and clang by default: Nov 4, 2009 · Which one is better to use among the below statements in C? static const int var = 5; or #define var 5 or enum { var = 5 }; Aug 24, 2010 · Macros (created with #define) are always replaced as written, and can have double-evaluation problems. Mar 4, 2017 · #define simply substitutes a name with its value. The preprocessor parses the source file and each occurrence of the name is replaced by its associated text. Since #define s are essentially just fancy text find-and-replace, you have to be really careful about how they're expanded. sbkxdc yjw xewi occez rdnnp ownn celt toilp nljotd igqnec