Check if PHP session has already started -

I have a PHP file, sometimes called a page that starts a session, Ever since the session started, so when I have the session_start () on this script, I sometimes get the "Session preceding" error message, The lines are inserted:

  if (! Isset ($ _COOKIE ["PHPSESSID"])) {session_start (); }  

But this time I got this warning message:

Notice: Undefined variable: _SESSION

is what This is a better way to check whether the session has already started.

If I use @ session_start , will it work properly and just stop the warnings? Recommended method for

Strong> PHP> = 5.4.0

Source:

PHP & lt; 5.4.0

  if (session_id () == '') {session_start (); }