原完整教程链接：6.7 Introduction to pointers

1.
// Best practice: When declaring a pointer variable, put the asterisk 
// next to the variable name.

2.
// Best practice: When declaring a function, put the asterisk of a 
// pointer return value next to the type.

3.
/*
   The size of a pointer is dependent upon the architecture the 
   executable is compiled for -- a 32-bit executable uses 32-bit 
   memory addresses -- consequently, a pointer on a 32-bit machine 
   is 32 bits (4 bytes). With a 64-bit executable, a pointer would be 
   64 bits (8 bytes). Note that this is true regardless of what is being 
   pointed to.
*/