C語言中const用法

const int a; /* a is const */
const int * const ip; /* The pointer *ip is const and what it points at is const */
int * const ip; /* The pointer *ip is const */
const int * ip; /* What *ip is pointing at is const */
int * ip; /* Nothing is const */
void fun(const int array[]); /* array[] is const, equal to const int * array */

const在*的左邊，則指針指向的變量的數值不可變；如果const在*的右邊，則指針指向的地址不可變(左数右指)。

ref: Here