Dummy

This is a discussion on Dummy within the C Programming forums, part of the General Programming Boards category; What would a definition for a dummy be in C and were should it be used Thanks!...

  1. #1
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    Lightbulb Dummy

    What would a definition for a dummy be in C and were should it be used Thanks!

  2. #2
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    #define DUMMY

    I'm not totally sure what you're asking, but I think you're referring to a dummy variable. A dummy variable is just a variable that you don't need, but that you use to make the calculation more clear. You would declare it like any other variable. In the following example, time is a dummy variable
    Code:
    // calculate position: x = x0 + v0 * t + 1/2 * a * t^2
    // no dummy variable
    x = x0 + v0 * (end_time - start_time) + 0.5 * a * (end_time - start_time) * (end_time - start_time);
    Code:
    // calculate position: x = x0 + v0 * t + 1/2 * a * t^2
    // with dummy variable, much cleaner
    int    time = end_time - start_time;
    x = x0 + v0 * time + 0.5 * a * time * time;

  3. #3
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    A dummy variable would be used in the case a function takes for example, an out reference parameter, where the caller has no interest in that particular bit of information.

    Windows message handlers and the bHandled parameter, are a place it commonly comes up.
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    Quote Originally Posted by Lost.at.C View Post
    What would a definition for a dummy be in C and were should it be used Thanks!
    I think it already contains the punch line!
    (Not meant against the OP Lost.at.C, but in general. There are lots.)

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