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 …
c - #Define VS Variable - Stack Overflow
Jun 18, 2012 · #define WIDTH 10 is a preprocessor directive that allows you to specify a name (WIDTH) and its replacement text (10). The preprocessor parses the source file and each …
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 …
c# - How do you use #define? - Stack Overflow
Oct 30, 2013 · The main use-case for #define is for conditional compilation (where it can be very useful). You're correct that using #define for symbols and (please don't do it) macros, is not a …
How to pass a variable into a YAML template parameter and use it …
Feb 15, 2025 · value: $(<variable-name>) # equivalent to: value: $[ variables[“variable_name”] ] # or value: $[ variables.variable_name ] As a macro is a shorthand for a runtime expression, …
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 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 …
What is the purpose of the #define directive in C++?
May 10, 2010 · 0 in C or C++ #define allows you to create preprocessor Macros. In the normal C or C++ build process the first thing that happens is that the PreProcessor runs, the …