Little question about postfix and prefix

This is a discussion on Little question about postfix and prefix within the C Programming forums, part of the General Programming Boards category; I thought this code: Code: { int myInt; myInt = 5; printf( "myInt++ ---> %d\n\n++myInt ---> %d", myInt++, ++myInt); } ...

  1. #1
    Registered User
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    May 2008
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    Unhappy Little question about postfix and prefix

    I thought this code:
    Code:
    {           int	myInt;
                 myInt = 5;
                 printf( "myInt++ ---> %d\n\n++myInt ---> %d", myInt++, ++myInt);
    }
    will yield:

    "myInt++ ---> 5

    ++myInt ---> 7"

    but it actually gave:

    "myInt++ ---> 6

    ++myInt ---> 7"

    with a warning: operation on 'myInt' may be undefined.

    Can some one help me out? I'm so confused by the result and the warning message.

  2. #2
    C++ Witch laserlight's Avatar
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    Read this C FAQ on expressions.
    C + C++ Compiler: MinGW port of GCC
    Version Control System: Bazaar

    Look up a C++ Reference and learn How To Ask Questions The Smart Way

  3. #3
    and the hat of sweating
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    Changing a variable more than once in a single statement is undefined.

  4. #4
    Registered User
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    Thank you guys very much.

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