How to declare function pointer in header and c-file?

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清歌不尽
清歌不尽 2020-12-31 02:12

I\'m a little confused over how to declare a function pointer in a header file. I want to use it in main and a file called menus.c and declare it in menus.h I assume. We wan

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  •  遥遥无期
    2020-12-31 02:43

    It's often helpful to use typedef with function pointers, so you can name the type to something descriptive:

    typedef void (*MenuFunction)(int);
    

    Then you would have a global variable of this type, probably in menus.c, and declared (with extern) in menus.h:

    static void my_first_menu_function(int x)
    {
      printf("the menu function got %d\n", x);
    }
    
    MenuFunction current_menu = my_first_menu_function;
    

    From main.c, you can then do:

    #include "menu.h"
    
    current_menu(4711);
    

    to call whatever function is currently pointed at by current_menu.

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