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volatile const int意思是C？(volatile const int meaning in C?)

 我正在读一本关于C的书 。它提到了一个对我来说没有意义的概念。 我所知道的是，编译器有时通过删除感觉不会影响表达式的变量来优化代码。 因此，如果我们将volatile指定给变量，则不会从任何表达式中删除此变量。  
 所以这本书介绍了这样的东西：  
volatile const int a = 1;
 
 解释只有几行，对我来说都没有意义。 有人可以解释为什么需要这样的变量？  
 PS：我理解volatile的概念，我不理解的是volatile const的概念。 

I am reading a book on C. It mentions a concept which does not make sense to me. What I know is that the compiler sometimes optimises code by removing variables which it feels would not affect an expression. So if we specify volatile to a variable, it does not remove this variable from any expression. 
So the book introduces something like this: 
volatile const int a = 1;
 
The explaination is only a couple of lines, none of which makes sense to me. Can somebody please explain why would be there a need of such a variable? 
PS: I understand the concept of volatile, what I dont understand is the concept of volatile const.

原文：https://stackoverflow.com/questions/20353499

更新时间：2024-03-31 17:03

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volatile const int意思是C？(volatile const int meaning in C?)

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