automatic-function-scope-variables.md

title	Automatic (Function Scope) Variables | Microsoft Docs
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ms.date	11/04/2016
ms.reviewer
ms.suite
ms.technology	cpp-tools
ms.tgt_pltfrm
ms.topic	error-reference
dev_langs	C++
helpviewer_keywords	automatic variables variables, automatic functions [C++], scope scope, declared within functions
ms.assetid	6e1a14c2-1fb0-4937-8628-8d963cc35ed4
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author	corob-msft
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manager	ghogen

Automatic (Function Scope) Variables

A variable declared within a function can only be used within the scope of that function.

// LNK2019_AV.cpp  
// compile with: /c  
void test(void);  
  
static int lnktest3 = 3;  
int lnktest4 = 4;  
  
int main() {  
   static int lnktest1 = 1;  
   int lnktest2 = 2;  
   test();  
}  

and then,

// LNK2019_AV_2.cpp  
// compile with: LNK2019_AV.cpp  
// LNK2019 expected  
extern int lnktest1;  
extern int lnktest2;  
extern int lnktest3;  
extern int lnktest4;  
  
void test(void) {  
   int i = 0;  
   i = lnktest1;  
   i = lnktest2;  
   i = lnktest3;  
   i = lnktest4;   // OK  
}  

See Also

Linker Tools Error LNK2019