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Structs ,pointers and functions - need some help

This is a discussion on Structs ,pointers and functions - need some help within the C Programming forums, part of the General Programming Boards category; Hi, could you please help me? I have a struct and I want to implement in with pointers and functions. ...

  1. #1
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    Question Structs ,pointers and functions - need some help

    Hi,
    could you please help me?
    I have a struct and I want to implement in with pointers and functions.
    Q - what is the corect syntax?

    for example:

    Code:
    typedef struct XYZ
    {
    
        int x;
        int y;
        int z;
       }XYZ_t;
    
    
    int func(  using the XYZ_t struct)
    {
      
    }
    
    int main()
    {
        
        XYZ_t *XYZ_t_PTR;
        func(  using the XYZ_t struct);
    }

  2. #2
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    That question is as unclear as mud.

    Your description of wanting to "have a struct" that is implemented "in with pointers and functions" is meaningless.
    Right 98% of the time, and don't care about the other 3%.

    If I seem grumpy or unhelpful in reply to you, or tell you you need to demonstrate more effort before you can expect help, it is likely you deserve it. Suck it up, Sunshine, and read this, this, and this before posting again.

  3. #3
    and the hat of int overfl Salem's Avatar
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    Which book are you reading?

    Because it isn't any good.

    Let me put it this way.

    If you had
    int *XYZ_t_PTR;

    would you still be as confused as you are now?
    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.
    I support http://www.ukip.org/ as the first necessary step to a free Europe.

  4. #4
    Stoned Witch Barney McGrew's Avatar
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    I have a struct and I want to implement in with pointers and functions.
    I don't think anyone can help you with that unless you become more specific about what "in" is.

    Q - what is the corect syntax?

    for example:

    Whatever that example is, it isn't valid C. I think you would benefit from learning the difference between objects and types.

    I'm wondering, do you have a reason to pretend that XYZ_t's underlying type isn't struct XYZ?

  5. #5
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    I think you mean something like this:

    Code:
    typedef struct XYZ
    Code:
    {
    
        int x;
        int y;
        int z;
       }XYZ_t;
    
    
    int func(XYZ_t *X) /* a pointer to struct */
    {
     X->x = 1;
    }
    
    int main()
    {
    
        XYZ_t *XYZ_t_PTR; /a pointer to struct */
    XYZ_t structXYZ; /The struct */
    XYZ_t_PTR = &structXYZ;
    
        func(XYZ_t_PTR);
    }
    


    Last edited by Ilkka Mannelin; 02-23-2013 at 03:15 AM.

  6. #6
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    Whhhhhhyyyy does everyone get taught to use typedef? It's a convenience to not have to type 'struct' all the time. Just a convenience.

    When I first encounted a C struct I was told to use typedef as well, and it confused the hell out of me (because it looks a bit like an anonymous definition, with this mysterious typedef keyword that I don't fully understand). Just seems like the two concepts always get bundled together too early for most people.

    Anyway. Mini rant over.

    Code:
    typedef struct XYZ
    { 
        int x;
        int y;
        int z;
       }XYZ_t;
     
    int func(XYZ_t *s)
    {   
    }
    
    int main()
    {     
        XYZ_t *XYZ_t_PTR;
        func(XYZ_t_PTR);
    }
    Is what I think you're asking. XYZ_t is a type name though not an instance of a struct. Your pointer points to nothing -- uninitialised garbage.
    AndiPersti likes this.

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