Detailed explanation based on the difference between session_unset and session_destroy_PHP tutorial

session_unset()
Release all $_SESSION variables currently created in the memory, but do not delete the session file and do not release the corresponding sessionid
session_destroy()
Delete the current user's corresponding session file and release the sessionid, the contents of the $_SESSION variable in the memory are still retained
Therefore, to release all the resources of the user's session, the following code needs to be executed sequentially:
Program code

If you just call session_destroy();
then echo $_SESSION['user'] is still valuable
That is, the content of the $_SESSION variable in the memory is still retained
[ Session]
session.save_handler = files ; Control method for saving/retrieving data
session.save_path = C:wintemp ; Parameters passed to the controller when save_handler is set to a file,
; this is the path where the data file will be saved. The folder must be created in advance
session.use_cookies = 1 ; Whether to use cookies 1 yes, 0 no
session.name = PHPSESSID
; The name of the session used in the cookie
session.auto_start = 0                                                                                                  _path = / ; Valid path of cookie
session.cookie_domain = ; Valid domain of cookie
session.serialize_handler = php ; Controller used to connect data
; php is the standard controller of PHP.
session.gc_probability = 1 ; Probability as a percentage of the 'garbage collection' process to start at each session initialization.
session.gc_maxlifetime = 1440 ; After the number of seconds indicated by the number here, the saved data will be considered
                                                 ;
Session.refer_check =; Check the http reference to make the additional include an additional IDS in the URLS. ION id
; session.entropy_length = 16
; session.entropy_file = /dev/urandom
session.cache_limiter = nocache; set to {nocache,private,public} to determine the HTTP
; cache Problem
session.cache_expire = 180 ; Document expires after n minutes
session.use_trans_sid = 1 ; Use transitional sid support if enabled at compile time ; ; --enable-trans-sid
url_rewriter.tags = "a=href,area=href,frame=src,input=src,form=fakeentry"