更改名稱的鏈接

Question

在此代碼中嘗試更改名稱i的鏈接。在C/C++中它合法嗎？

static int i = 2; 
int i; 

int main() 
{ 
    return 0; 
} 

Answer 1

在C++是形成不良的代碼（你有多個定義變量i）即需要標準一致性編譯器來發出錯誤消息

$ 3.2.1（C++ 03）

No translation unit shall contain more than one definition of any variable, function, class type, enumeration type or template.

在C99您的代碼調用未定義行爲，因爲6.2.2/7說

If, within a translation unit, the same identifier appears with both internal and external linkage, the behavior is undefined.

Answer 2

號在CI得到這個錯誤：

test.c:2: error: non-static declaration of ‘i’ follows static declaration
test.c:1: note: previous definition of ‘i’ was here

在C++中，這些：

test.cpp:2: error: redefinition of ‘int i’
test.cpp:1: error: ‘int i’ previously defined here