指针是一个特殊的变量，它里面存储的数值被解释成为内存里的一个地址。要搞清一个指针 需要搞清指针的四方面的内容：指针的类型，指针所指向的类型，指针的值或者叫指针所指 向的内存区，还有指针本身所占据的内存区。-Pointer is a special variable, the value stored inside it is interpreted as a memory address. To find out the pointer to a pointer needs to fin