Understanding of pointers

1. Pointer definition

( First level pointer )

 

 （ The secondary pointer ）---- Continued above

 

 

2. test

（ First level pointer ）

（ The secondary pointer ）

 3. If the formal parameter of a function is a pointer , Then the actual parameters of the call I want the address , If you need Take the address symbol & It depends on the actual parameter itself yes Variable still The pointer . yes Variable , To get the address , yes The pointer Don't To get the address .

 

---- When a pointer is assigned ,*p=&i And p=&i What's the difference? ？

    1.*p=&i The result is *p The value of is a variable i The address of ;p=&i The result is p Point to variable i The address of ,*p The value of is i.    2.*p Represents the value of the address pointed to by the reference pointer .（ The pointer of the pointer ）
       *p=&i,p It's a secondary pointer , namely p Point to another pointer , Then the pointer points to i The address of , Or indirectly i Of Address .
        p=&i, Express p Direct to i The address of .