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 preprocessor - Is there a good reason for always enclosing a …
#define _add_penguin(a) penguin ## a #define add_penguin(a) _add_penguin(a) #define WIDTH (100) #define HEIGHT 200 add_penguin(HEIGHT) // expands to penguin200 …
How to declare variable and use it in the same Oracle SQL script?
I want to write reusable code and need to declare some variables at the beginning and reuse them in the script, such as: DEFINE stupidvar = 'stupidvarcontent'; SELECT stupiddata FROM …
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 …
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 …
How do I show the value of a #define at compile-time?
I know that this is a long time after the original query, but this may still be useful. This can be done in GCC using the stringify operator "#", but it requires two additional stages to be defined first. …
define volumes in docker-compose.yaml - Stack Overflow
Aug 4, 2021 · I am writing a docker-compose.yaml file for my project. I have checked the volumes documentation here . I also understand the concept of volume in docker that I can mount a …
Advantage and disadvantages of #define vs. constants?
Dec 22, 2009 · Can someone point out the advantages and disadvantages of using #define versus constants? Most of my work is done in C and Objective-C.
#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...
What's the difference in practice between inline and #define?
Aug 24, 2010 · Macros (created with #define) are always replaced as written, and can have double-evaluation problems. inline on the other hand, is purely advisory - the compiler is free …