Thread: Creating instance of a structure

  1. #1
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    Creating instance of a structure

    Hello everyone I am trying to learn C and I am relative new to the language but I did programming in Java before.

    My Problem is I have the following structure

    Code:
    struct FluxCapacitor 
    {
        unsigned char* c_string;
        unsigned int value 
    };
    And now I want to write a function like this

    Code:
    struct FluxCapacitor* createFluxCapacitor()
    In the function I want to create a new instance of my struct and initialize my attributes with random values. Can someone explain to me how to do this in c?

    Thanks for your help !
    Last edited by Jimmy589; 04-05-2017 at 05:51 AM.

  2. #2
    and the hat of int overfl Salem's Avatar
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    You basically need
    Code:
    struct FluxCapacitor *newfp = malloc( sizeof(*newfp) );
    if ( newfp ) {
      newfp->value = 88; // MPH needed to trigger
    }
    return newfp;
    The caller will need to deal with the possibility that nothing was created (the function returned NULL).
    If you dance barefoot on the broken glass of undefined behaviour, you've got to expect the occasional cut.
    If at first you don't succeed, try writing your phone number on the exam paper.

  3. #3
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    Well thanks for your help in first place but I need to fill the attributes with random values so canīt I just do it like this

    Code:
    newfp->value = rand();

  4. #4
    and the hat of int overfl Salem's Avatar
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    *sigh*

    Try it and find out.
    If you dance barefoot on the broken glass of undefined behaviour, you've got to expect the occasional cut.
    If at first you don't succeed, try writing your phone number on the exam paper.

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