Operation Session with Thinkphp

Wrote a piece of code to perform some common operations on the session:

<?phpnamespace Home\controller; UseThink\controller;classDemo1controllerextendsController { Public functionindex () {$user= M ("City")Select (); $this->assign (' list ',$user); $this-display (); }        //Session Assignment     Public functionTest1 () {session (' username ', ' admin '); Session (' Useralias ', ' admin '); Echo' Session assignment '; }        //Session Fetch Value     Public functiontest2 () {Echo' Session value <br/> '; Echo' Username: '. session (' username '). ' <br/> '; Echo' Useralias: '. session (' Useralias '). ' <br/> '; }        //Delete Session     Public functionTest3 () {session (' Username ',NULL); Session (' Useralias ',NULL); Echo' Delete Session '; }        //determine if the session exists     Public functiontest4 () {if('? Username ')) {            Echo' Username exist <br/> '; } Else {            Echo' username does not exist <br/> '; }                if('? Useralias ')) {            Echo' Useralias exists '; } Else {            Echo' Useralias does not exist '; }    }}

Operation session with thinkphp