Q167748: PRB: Variable Scope in for-statement Extends Beyond Loop

Article: Q167748
Product(s): Microsoft C Compiler
Version(s): 5.0,6.0
Operating System(s): 
Keyword(s): kbLangCPP kbVC500 kbVC600
Last Modified: 11-JUN-2002

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The information in this article applies to:

- The C/C++ Compiler (CL.EXE), included with:
   - Microsoft Visual C++, 32-bit Editions, versions 5.0, 6.0 
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SYMPTOMS
========

If you declare the same variable in two different for-statements, the following
error may appear:

  Test.cpp(4) : error C2374: 'i' : redefinition; multiple initialization

CAUSE
=====

The scope of a variable declared in the initialization part of a "for" loop is
given local scope, as if it had been declared immediately prior to the
for-statement.


RESOLUTION
==========

Compile with /Za, Disable Language Extensions. To select this option in
Developer Studio, select Project, Settings, and then click the C/C++ Tab. Change
the Category to Customize and select Disable Language Extensions.

If you cannot use the /Za option, you can work around the problem by #defining
the "for" keyword as follows:

  #define for if(0);else for

MORE INFORMATION
================

  /* Compile Options Needed to compile without error: /Za */ 

   /* test.cpp */ 
   void main()  {
  for (int i=0; i<10; i++)
     ;
  for (int i=0; i<15; i++)
     ;
   }

Additional query words:

======================================================================
Keywords          : kbLangCPP kbVC500 kbVC600 
Technology        : kbVCsearch kbAudDeveloper kbCVCComp
Version           : :5.0,6.0
Issue type        : kbprb

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