compiler-warning-level-1-c4258.md

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Learn more about: Compiler Warning (level 1) C4258	Compiler Warning (level 1) C4258	11/04/2016	C4258	C4258	bbb75e6d-6693-4e62-8ed3-b006a0ec55e3

Compiler Warning (level 1) C4258

'variable' : definition from the for loop is ignored; the definition from the enclosing scope is used"

Under /Ze and /Zc:forScope, variables defined in a for loop go out of scope after the for loop ends. This warning occurs if a variable with the same name as the loop variable, but defined in the enclosing loop, is used again in the scope containing the for loop. For example:

// C4258.cpp
// compile with: /Zc:forScope /W1
int main()
{
   int i;
   {
      for (int i =0; i < 1; i++)
         ;
      i = 20;   // C4258 i (in for loop) has gone out of scope
   }
}