Changing a input string to a function call?

This is a discussion on Changing a input string to a function call? within the C Programming forums, part of the General Programming Boards category; Is it possible to change a input string for example sin(pi*x), whereby in the code i have the variables pi ...

  1. #1
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    Changing a input string to a function call?

    Is it possible to change a input string for example sin(pi*x), whereby in the code i have the variables pi and x, such that i can call the sine function as given by the input string. Without having to do string comparison and if statments, as for any general equation composed of sines and exponets and powers this would be really cumbersome
    Thanks

  2. #2
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    so you want to take a string and stick in the vars data and not its name.

    look into sprintf

  3. #3
    Registered User Vber's Avatar
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    you mean, you have in a string "sin(pi*x)" and you want to call it directly by the string? I don't think it's possible. But, if you have pi and x defined in your code, just call it, but not from a string

    If I understand you correct, checkout also the sprintf function.

  4. #4
    ATH0 quzah's Avatar
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    The answer you want: Yes.
    Code:
    #include <magic.h>
    
    int main( void )
    {
        struct MagicItem magicWand;
        wave( magicWand );
    
        return 0;
    }
    Reality: No.

    You have to set up a parser of some kind for your input, so it knows what the hell you're trying to do. You cannot simply read a string from the keyboard, and without using any checking at all, have it call a function and create variables to display output.

    Quzah.
    Hope is the first step on the road to disappointment.

  5. #5
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    It's all their fault!! Those stupid guys who have created the C language haven't considerned to make the language understand a string when it is the same as a function and call the function!!
    Loading.....
    ( Trying to be a good C Programmer )

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