Convert a long to negative?

This is a discussion on Convert a long to negative? within the C++ Programming forums, part of the General Programming Boards category; This is something really easy but my brain is struggling today. I have a long which has a value of ...

  1. #1
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    Convert a long to negative?

    This is something really easy but my brain is struggling today. I have a long which has a value of 10. I want to convert it to negative (i.e. -10)

    I am using

    lValue = lValue - (lValue * 2);

    There has to be a simpler bit swapping way of doing it.

  2. #2
    C++ Witch laserlight's Avatar
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    Yeah, like:
    Code:
    lValue = -lValue;
    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

  3. #3
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    See, I said my brain had given up for the day.

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