C言語でヌルポインタとは何ですか?

void *pointername;

* ( (type cast) void pointer)

int i=10; void *vp; vp = &i; printf ("%d", * ((int*) vp)); // int * type cast

#include main ( ){ int i =10; float f = 5.34; void *vp; vp = &i; printf ("i = %d", * ((int*)vp)); vp = &f; printf ( "f = %f", * ((float*) vp)); }

i = 10 f = 5.34

#include #define MAX 20 int main(){ int array[5] = {12, 19, 25, 34, 46}, i; void *vp = array; for(i = 0; i < 5; i++){ printf("array[%d] = %d
", i, *( (int *)vp + i ) ); } return 0; }

array[0] = 12 array[1] = 19 array[2] = 25 array[3] = 34 array[4] = 46