order of evaluation of C-expression

This is a discussion on order of evaluation of C-expression within the C Programming forums, part of the General Programming Boards category; Can anyone explain why output of following program excerpt gives value '6' for x ? int x=8; x-=--x-x--;//how this statement ...

  1. #1
    Registered User
    Join Date
    Nov 2009
    Posts
    1

    order of evaluation of C-expression

    Can anyone explain why output of following program excerpt gives value '6' for x ?

    int x=8;
    x-=--x-x--;//how this statement will be processed
    printf("%d",x);

  2. #2
    C++ Witch laserlight's Avatar
    Join Date
    Oct 2003
    Location
    Singapore
    Posts
    23,803
    Because the behaviour is undefined as x is modified more than once between consecutive sequence points.
    Quote Originally Posted by Bjarne Stroustrup (2000-10-14)
    I get maybe two dozen requests for help with some sort of programming or design problem every day. Most have more sense than to send me hundreds of lines of code. If they do, I ask them to find the smallest example that exhibits the problem and send me that. Mostly, they then find the error themselves. "Finding the smallest program that demonstrates the error" is a powerful debugging tool.
    Look up a C++ Reference and learn How To Ask Questions The Smart Way

Popular pages Recent additions subscribe to a feed

Similar Threads

  1. Replies: 6
    Last Post: 11-11-2009, 01:27 PM
  2. Screwy Linker Error - VC2005
    By Tonto in forum C++ Programming
    Replies: 5
    Last Post: 06-19-2007, 02:39 PM
  3. recursion error
    By cchallenged in forum C Programming
    Replies: 2
    Last Post: 12-18-2006, 08:15 AM
  4. Please Help - Problem with Compilers
    By toonlover in forum C++ Programming
    Replies: 5
    Last Post: 07-23-2005, 10:03 AM
  5. sizeof and Expression Evaluation
    By Dave_Sinkula in forum C Programming
    Replies: 2
    Last Post: 08-11-2003, 07:11 PM

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21