Int * indicates the type of poInter P, and int specifies its pointer type, that is, the maximum offset of the address pointed to by P is 4 bytes every time it is accessed by+1;

* indicates that P is a pointer, and when used, P is used as a variable identifier;

*p identifies the value of the address where P is located, *p=9, which means that the address space pointed by P is assigned to 9;

int * p； ? Indicates that the integer pointer variable p is declared;

Int * p = & ampnum indicates that an integer pointer variable is declared and points to an address space.

* p = 9； This sentence is to assign a value to the address space pointed by p, that is, to assign a value to num, not to assign a value to p itself.