% 与 & 操作符

int index = 31;
// 2 的 幂次才可以的
int modeNum = 16;
Debug.Log(string.Format("{0} % {1} = {2}", index, modeNum, index % modeNum));
int andOptNnum = modeNum - 1;
Debug.Log(string.Format("{0} & {1} = {2}", index, andOptNnum, (andOptNnum & index)));