What is the difference between WIN64 and _WIN64 preprocessor directives


  • Hi,

    I am not expertise in C++, I know that these are using to check the current OS. but would like to know the difference.

     in project options / Configuration properties / C-C++ /
    Preprocessor => Preprocessor Definitions
    we define in preprocessor directive as WIN64 and while using in the code we use _WIN64, please clarify with underscore ( _ ) and without underscore in "WIN64" preprocessor directive. 


    • Moved by Paul Zhou Friday, March 18, 2011 9:14 AM off-topic (From:64-Bit .NET Framework Development.)
    Wednesday, March 16, 2011 4:25 PM

All replies

  • Hi Sarvanan,


    Welcome to the MSDN forum!


    I’d like to move your thread to off-topic because your question is not related to this forum.

    I suggest that you can post in PCW Forum, there are experts in that forum.


    Thank you for your understanding.

    Paul Zhou [MSFT]
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    Friday, March 18, 2011 9:13 AM
  • Hi,

    I did not receive any update posting this Query in PCW forum.



    Monday, March 28, 2011 3:42 PM