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.
*/
