[embedded C foundation] Part 9: basic usage of C language pointer

1 summary

Address ：
The number that distinguishes different memory spaces is called address

The pointer ：
The pointer is the address , The address is the pointer

Pointer to the variable ：
Variables that store pointers are called pointer variables

32bit Operating system , Pointer 4 byte ;
64bit Operating system , Pointer 8 byte

1.1 Definition of pointer

int *p; //p There's an address in it ,p Itself is a pointer variable
char *p;
float *p;

1.2 Pointer operated variable

There are two ways to manipulate variables :
1. Direct access
Use variable names to access

2. Indirect access to
Use pointers to access

&: Fetch address operator
*: Take the space operator

1.3 The arithmetic operation of the pointer

+
-

++: Pointer to memory high address offset points to data type space size bytes 
--: Pointer to memory low address offset points to data type space size bytes 

Example ：