c++ - Why use #define instead of a variable - Stack Overflow
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.
What is the difference between #define and const? [duplicate]
The #define directive is a preprocessor directive; the preprocessor replaces those macros by their body before the compiler even sees it. Think of it as an automatic search and replace of your …
Is it possible to use a if statement inside #define?
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 …
Why do most C developers use define instead of const?
Mar 4, 2017 · #define simply substitutes a name with its value. Furthermore, a #define 'd constant may be used in the preprocessor: you can use it with #ifdef to do conditional compilation …
Why are #ifndef and #define used in C++ header files?
I have been seeing code like this usually in the start of header files: #ifndef HEADERFILE_H #define HEADERFILE_H And at the end of the file is #endif What is the purpose of this?
Difference between `constexpr` and `#define` - Stack Overflow
Feb 12, 2021 · 23 So I read the interesting answers about what are the differences between constexpr and const but I was curious about are the differences between #define and …
How do I define a function with optional arguments?
How do I define a function with optional arguments? Asked 13 years, 8 months ago Modified 1 year, 4 months ago Viewed 1.2m times
error Please #define _AFXDLL or do not use /MD [d] occurs even …
Jul 30, 2014 · Check what Michael said: in the build log, is there a _AFXDLL? Do not define it manually, it is added when you set "Use MFC in a shared DLL". If it is set there, this sounds …
c++ - 'static const' vs. '#define' - Stack Overflow
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?
#define FOO 1u 2u 4u ... What does 1u and 2u mean?
I'm working with the HCS12 MCU, and this was part of the library. I'm just wondering what the 1U, 2U, 4U, 8U... means in this code. I'm still learning how to use classes, please try to explain thi...