总的来说，我更喜欢坚持使用YAGNI，不要盲目安抚各种编码风格指南.相反，我首先查看他们的基本原理是否适用于特定情况(如果编码风格指南没有基本原理，那么它是一个糟糕的)，如果显然没有，那么就没有理由应用该指南到那种情况.Typically, the way I'd define a true global constant (lets say, pi) would be to place an extern const in a header file, and define the constant in a .cpp file:constants.h:extern const pi;constants.cpp:#include "constants.h"#include <cmath>const pi=std::acos(-1.0);This works great for true constants such as pi. However, I am looking for a best practice when it comes to defining a "constant" in that it will remain constant from program run to program run, but may change, depending on an input file. An example of this would be the gravitational constant, which is dependent on the units used. g is defined in the input file, and I would like it to be a global value that any object can use. I've always heard it is bad practice to have non-constant globals, so currently I have g stored in a system object, which is then passed on to all of the objects it generates. However this seems a bit clunky and hard to maintain as the number of objects grow.Thoughts? 解决方案 It all depends on your application size. If you are truly absolutely sure that a particular constant will have a single value shared by all threads and branches in your code for a single run, and that is unlikely to change in the future, then a global variable matches the intended semantics most closely, so it's best to just use that. It's also something that's trivial to refactor later on if needed, especially if you use distinctive prefixes for globals (such as g_) so that they never clash with locals - which is a good idea in general.In general, I prefer to stick to YAGNI, and don't try to blindly placate various coding style guides. Instead, I first look if their rationale applies to a particular case (if a coding style guide doesn't have a rationale, it is a bad one), and if it clearly doesn't, then there is no reason to apply that guide to that case. 这篇关于使全局“常量"的正确方法在 C++ 中的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！ 上岸，阿里云！
