Pointers provide for machine - independent address arithmetic 指针可以提供独立于机器的地址运算
The common type system also provides three byte - based address arithmetic operations on pointer types : adding integers to and subtracting integers from pointers , and subtracting one pointer from another 通用类型系统还对指针类型提供了三种基于字节的地址算法操作:向指针加上整数,从指针减去整数,以及从一个指针减去另一个指针。