How can we get the error when there is a problem to upload a file?
$_FILES contains the error code associated with the uploaded file.
What is the difference between $_FILES[‘userfile’][‘name’] and $_FILES[‘userfile’][‘tmp_name’]?
$_FILES represents the original name of the file on the client machine, $_FILES represents the temporary filename of the file stored on the server.
What does $_FILES means?
$_FILES is an associative array composed of items sent to the current script via the HTTP POST method.
What does $_SERVER mean?
$_SERVER is an array including information created by the web server such as paths, headers, and script locations.
What does $GLOBALS mean?
$GLOBALS is associative array including references to all variables which are currently defined in the global scope of the script.
What is the difference between session_unregister() and session_unset()?
The session_unregister() function unregister a global variable from the current session and the session_unset() function frees all session variables.
When do sessions end?
Sessions automatically end when the PHP script finishes executing but can be manually ended using the session_write_close().
What is the meaning of a Persistent Cookie?
A persistent cookie is permanently stored in a cookie file on the browser’s computer. By default, cookies are temporary and are erased if we close the browser.
How can you propagate a session id?
You can propagate a session id via cookies or URL parameters.
How to initiate a session in PHP?
The use of the function session_start() lets us activating a session.