I need help creating three functions for my dynamic array C# class da.c

The three functions are declared in da.h that i need help with

extern DA *newDA(void);

extern void setDAdisplay(DA *,void (*)(void *,FILE *));

extern void setDAfree(DA *,void (*)(void *));

This is the header file

and the Method behavoir for these functions are

newDA - The constructor returns an initialized DA object.

setDAdisplay - This method is passed a function that knows how to display the generic value stored in an array slot.

setDAfree - This method is passed a function that knows how to free the generic value stored in an array slot.

And assertion for newDA is the that the memory allocated shall not be zero.

Thanks so much

#ifndef DA INCLUDED #define DA INCLUDED- #include typedef struct da DA; extern DA *wDA (void); extern void setDAdisplay (DA ,void ()(void ,FILE *)) extern void setDAfree (DA *,void (*) (void *)); extern void insertDA (DA *items,int index,void *value); extern void *removeDA(DA *items,int index); extern void unionDA(DA recipient, DA *donor); extern void *getDA (DA *items,int index); extern void *setDA (DA *items,int index, void *value); extern int sizeDA(DA *items); extern void displayDA (DA *items, FILE *fp); extern int debugDA(DA *items ,int level); extern void freeDA(DA *items); #endif