View and change sessions variables in a browser

Question

Debugging a PHP program, is there any add-on/plug-in for browser which I can view sessions variables (those PHP $_SESSION["foobar"] )?

Best if I can change the value in the variables.

Answer 1

There is no way to manipulate the values stored in sessions from the client side.

That's one of the main reasons you'd use a session over a cookie - YOU control the data. With cookies, the user can manipulate the data.

The only way to access/manipulate session data from the client side would be with an Ajax call or other JavaScript mechanism to call another php script, which would be doing the retrieval/manipulation of the session data via the session_ functions.

Answer 2

$_SESSION is a server-side array of variables. If we could read or change the values, there are many things that we could do to hack or cause other bad things to happen.

However, using phpinfo(); we can view session variables - but we cannot change the value.

Even better, we can debug all session variables with

print_r($_SESSION);  //if you echo "<pre>" before, and a closing "</pre>" after, it prints very cleanly. 

some other useful commands:

session_start(); // start session  -- returns Session ID session_destroy(); // unset all session variable 

Session is an array so if you set $_SESSION['key']='value'; it is same like $array['key']=value; - only, what is special about $_SESSION - is that it persists until the window is closed, or session_destroy() is called.