$_SERVER['PHP_SELF']; I don’t know what the following PHP_SELF means
Chen2022-01-04 15:39:02
$_SERVER['PHP_SELF'] The file name of the currently executing script, related to the document root.
For example, using $_SERVER['PHP_SELF'] in a script at http://example.com/test.php/foo.bar will result in /test.php/foo.bar.
https://www.runoob.com/php/php-superglobals.html
Chen2022-01-04 15:37:32
$_SERVER['PHP_SELF']
The file name of the currently executing script is related to the document root.
For example, using $_SERVER['PHP_SELF'] in a script at http://example.com/test.php/foo.bar will result in /test.php/foo.bar.
https://www.runoob.com/php/php-superglobals.html