How to understand static void * a = & a;?

how to understand this line of code? 

 static void * a = &a;

I saw it on the source code of AFN. 

static void *AFHTTPRequestSerializerObserverContext = &AFHTTPRequestSerializerObserverContext;
The

AFURLRequestSerialization.h file is used when serializing.
this style of code has been seen several times elsewhere.

Zhihu has the same problem ,

the answer is
this is a static untyped pointer an and then assigning it to a with a pointer drop address is an initialization. That is, a pointer pointing to a pointer.

I don"t quite understand. I don"t think the explanation is very clear for several answers.

I"ll ask again here.

C afnetworking3.0 objective-c cPP
Mar.06,2021

two steps
first declare 

static void * a

an is a pointer to an address, which itself has an address

then 

*a = &a

point the address pointed to by a to the address pointed to by a pointer 

static void * a = &a;

take it apart and see:

  • & an is a pointer to a and is a memory address
  • void * is an untyped pointer. Static has no effect on interpretation. The pointer points to the memory address of a
    • .

to sum up, it is the pointer to the pointer (& a) (void *)

this is a way to initialize untyped (void) pointers by assigning the pointer's address to the pointer itself, for example.

What is the purpose of this definition of 
  
?

Previous: After the vue parent component updates the data through the ref call child component method, the view is not updated

Next: Css typesetting problem

css mysql arrays josn react html typescript webpack npm sass R objective-c .net sql-server jquery python-3.x angularjs django angular excel regex iphone ajax linux xml pandas vba spring database wordpress string wpf xcode windows bash postgresql oracle multithreading eclipse list firebase algorithm macos forms image scala visual-studio azure bootstrap spring-boot react-native python-2.7 docker performance function winforms matlab powershell apache dataframe api sqlite numpy rest shell selenium flutter dart maven loops qt swing android-studio csv express file class tensorflow sorting codeigniter perl
MySQL Query : SELECT * FROM `codeshelper`.`v9_news` WHERE status=99 AND catid='6' ORDER BY rand() LIMIT 5
MySQL Error : Disk full (/tmp/#sql-temptable-64f5-1e5bf3f-45683.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
MySQL Errno : 1021
Message : Disk full (/tmp/#sql-temptable-64f5-1e5bf3f-45683.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
Need Help?