同一个内存地址有两个不同的值

22 0x22ff74

33 0x22ff74

为什么同一个地址会有两个不同的值?

为什么同一个地址会有两个不同的数据?

没有.允许编译器优化对 const 的任何提及，就好像您在其中编写了它的编译时值.

请注意，如果您执行诸如写入为 const 保留的内存之类的讨厌的技巧，编译器也可以在您运行它时生成擦除硬盘的代码.

Code

#include <iostream>
using namespace std;

int main() {
    const int N = 22;
    int * pN = const_cast<int*>(&N);
    *pN = 33;
    cout << N << '	' << &N << endl;
    cout << *pN << '	' << pN << endl;
}

Output

22 0x22ff74

33 0x22ff74

Why are there two different values at the same address?

Why are there two different datas at the same address?

There aren't. The compiler is allowed to optimize any mention of a const to be as though you had written its compile-time value in there.

Note that the compiler is also allowed to generate code that erases your hard disk when you run it if you do nasty tricks like writing to memory reserved for consts.

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